The movies jumped the shark in Star Trek II; when they decided Kirk that never dropped all charges in "Space Seed," and that planets explode like in Superman... and that terraforming devices can be more powerful than actual explosives.

Just a giant cluster-mess.

"In nearly every aspect, Jackson's choices either were faithful to the book or made sense" 

Except that Tolkien's intention, was that the entire story was about keeping Arwen safe, to restore the line of Luthien; so she couldn't be mentioned in the story except in ing.

But in the film, Luthien just becomes "some elf-maid who loved a mortal and died."

And there's your answer "why..." Jackson was a teenager playing with matches in an art-museum.

>>"Tbf, taking 3 books packed to the brim with lore and condensing it down to 3ish hours is a massive undertaking."

Especially when he doesn't understand the author's intent-- and didn't want to ask the world's top expert, Christopher Tolkien.

So of course it simply became a silly fantasy-film.

Aragorn did not have Elvish blood; Numenoreans were not Elves, except from being of the Children of Luthien (who the movie said was just "some Elf-maid who loved a mortal... she died.")

As for Elvish blood, that was Boromir, from his mother Finduilas; and so Boromir was much like Feanor, in being proud and devoted to his father, and having a desire to become king himself.

Faramir, meanwhile, was more like his father, in being true of the blood of Numenor; and so he saw right through the danger of the Ring-- and its plot to test him, by giving him the option to take it-- and he had every right to do so, just like Aragorn and Isildur.

Faramir didn't need a "hobbit on his shoulder" to tell him the right choice!

In fact, Sam blabbed about the Ring, because he sensed Faramir's Numenorean wisdom.

So Jackson simply corrupted all of the book-characters, in the same way that he missed the entire plot from beginning to end.

He was simply out of his depth.

>>"Jackson had to make a lot of changes to Tolkien's story to capture the gist of it over three feature-length movies."

No he didn't. He just showed that he didn't understand Tolkien's story.

Particularly the Ring, with Aragorn saying:

"We cannot wield it!

None of us can.

It is Sauron's Ring, and answers to him alone."

And then, we get conflicting s about how Gandalf and Galadriel could become powerful by using it, and Boromir wants to use it... but how only Sauron can "bend it to his will."

Meanwhile the film says that Saruman wants Sauron to have the Ring--

which completely misses the plot, since the whole story is about how Sauron only comes to power in the first place, because Saruman wanted to get the Ring for himself.

When in the book, Elrond says that they all indeed had the power to wield it, and could defeat Sauron at any time by using the Ring;

but that they simply could not wield it, without being corrupted by it themselves.

(Which Boromir doubts, thinking that good intentions would keep Men from being corrupted, and that other species were just weak).

And the book expressly says that Sauron fears Aragorn, simply because Aragorn could use the Ring to become a great and powerful lord, and defeat Sauron.

And so when Frodo uses the Ring's power on Gollum, only to make him get out of Frodo's way to destroying the Ring; then Frodo becomes corrupted, and cannot destroy it even at the end, but instead claims it for his own.

So the films give a very vague and confused explanation of the Ring, saying both that they couldn't use it, and that they would be corrupted by it.

But if they couldn't use it to defeat Sauron, then there was real temptation to use it-- and so, no real moral; other than their simply being foolish for believing that they could use it to defeat him, when they really couldn't.

When actually, Tolkien's moral was that they could defeat the enemy by sinking to his level, but then they would become even worse.

Neither Bilbo or Sam used the Ring's power on anyone, like Frodo did on Gollum.

As for Sauron, he was already corrupt when he made the Ring, as well as his entire plan to use it to enslave the Elves.

The movies were a setup to the TV-show, since everyone just said "OH, YOU HAVE TO MAKE CHANGES, FILM IS DIFFERENT FROM BOOKS" to excuse every deviation from the story.

So the TV series simply continued this rationalization, and fans got what they asked for.

No, not all; Bombadil could not be corrupted by it.

However he also could not care about its destruction, either, or even understand its danger.

The Ring's corrupting influence, came from having the heart to wield power over others, whether for good or evil; and Frodo sensed that Bombadil did have this.

Which is why Frodo gave the Ring to Bombadil without hesitation; though he was reluctant to give it to Gandalf:

i.e. since Gandalf indeed was very powerful and persuasive.....

and Gandalf also said that Bombadil could not affect the Ring's power over others.

So Frodo simply knew that Bombadil could not desire the Ring, and gave it to him on request.

So once Frodo used the Ring's power on Gollum, then Frodo fell under the Ring's power-- just as Elrond warned., at the Council.

>>"Frodo succumbed to the One Ring's influence because of his sheer exhaustion, even though he'd put up a strong fight against it prior to that point."

No. He USED the Ring's power on Gollum, to defeat Sauron; and so while he then said he would destroy the Ring, he fell under its power as a result of USING its power.

As Elrond said at the Council, if anyone defeated Sauron by using his own Ring, then they would become evil just like Sauron, and could not destroy the Ring.

And that's exactly what happened on Mt. Doom: once Frodo used the Ring's power, he was corrupted by it as well.

And that's why they couldn't use the Ring.

Unfortunately, in the films, they say that they lack the ABILITY to use the Ring; but in the book, they simply were unable to use it without being corrupted themselves.

And that was the real moral of Tolkien's story; since most people believe that power cannot corrupt them personally, or their favorite leaders, like it can the enemy.

"Yes, Palpatine may have hid himself in the Force so that the Jedi did not know he was a Sith Lord, but the Jedi still should have perceived Palpatine as a corrupt politician."

That's why he arranged his own kidnapping by General Grievous, to puff up the Jedi's egos, and make them feel heroic and powerful; and make himself look weak, and in need of their protection.

It was the standard "damsel in distress" act.

Also, Kirk became Will Decker's mentor, after Will lost his father to The Doomsday Machine; with Will Decker being promoted to captain of the Enterprise and overseeing the refit, and the end of Kirk's 5-year mission and promotion to iral.

We already saw from "The Doomsday Machine" that Kirk was a good friend of Matt Decker's; and so it made sense that he took over in the role of Will's mentor after his father died.

Unfortunately, the movie was silent on this, when a single line of dialogue could have done it.

They weren't the same character.

Will Decker was Matt Decker's son, from "The Doomsday Machine;" and Kirk became Will's mentor after both Kirk and Will lost him in the line of duty.

Also:

Will Decker is the son of Matt Decker, who gave his life in trying to destroy the Doomsday Machine-- and ultimately succeeding, when it gives Kirk the knowledge on how to do it with the rest of Decker's ship.

While this happens, Will Decker is a Starfleet officer after his father.

So after this, Kirk becomes Will Decker's mentor, essentially his godfather, and so Will Decker becomes captain of the Enterprise, overseeing the refit, as Kirk is promoted to iral upon finishing the 5-year mission.

This explains the backplot of Kirk's relationship with Will Decker, tying it to the original series in "The Doomsday Machine" and Kirk's implied long friendship with Matt Decker.

Except for one thing:

Saruman, not Sauron, was the true villain of the story; and Gandalf dies because of Saruman, so he is brought back by Eru to replace Saruman for that reason.

Gandalf didn't simply get a "do-over" because of who he is; he's Gandalf not Batman.

That's not it.

Gandalf refused to be head of the order of wizards, whose task was to defeat Sauron; and Saruman took the role instead, while Gandalf opted for more secret and dangerous work in defeating Sauron-- in which Gandalf trusted Saruman, for the most part.

But has he delved deeper into Sauron's lore, Saruman tried to replace Sauron instead, as supreme ruler of the world, by trying to get the One Ring; while justifying it with half-truths; as he says, "the white light can be broken," calling himself "Saruman of many colors--" and to which Gandalf says "in which case it is no longer white," i.e. no longer the truth.

So when Gandalf dies because of Saruman's treachery, Eru brings him back to replace Saruman as head of the order, and with the power to remove him entirely-- which he does, breaking his staff and taking away his power, for his arrogance.

If anyone was a Christ-like figure, it was Aragorn; since he was tasked with accepting death for the treachery of Numenor, to face the fear of it that was instilled by Morgoth, and which caused his people to commit treason against the Valar out of failed faith in Eru.

Except Jon Snow was one of a number of characters who couldn't die.

Gandalf, meanwhile, was simply brought back by Eru due to Saruman's treachery; since Gandalf was originally meant to be head of the order, but he refused it in order to take on more dangerous assignments.

And so Gandalf's death was due to Saruman's doings-- not Saurons.

In the book, Gandalf says that if Sauron got the Ring back, then he could not foresee his rule ever ending-- meaning that there would be no more second chances.

So Gandalf's return was not a deus ex machina, but a divine karmic-device for Saruman's betrayal against his entire purpose in Middle Earth, to lead the quest to defeat Sauron in the Third Age.

But instead, Saruman tried to take Sauron's place, thus allowing Sauron to rise to power at all; while if Saruman had remained true, then he could have defeated Saruman centuries earlier.

Saruman did not simply fail; he deliberately betrayed the trust of Eru and the Valar, seeking the Ring that he swore to destroy; which is what caused Gandalf to fail and die.

So Eru made an exception for that reason, and promoted Gandalf to Saruman's place as head of the Order of Wizards-- and thus, the authority to cast Saruman out entirely, when he will not repent, taking away his power as a wizard.

Saruman, not Sauron, was the story's true villain; just like Sam, not Frodo, was the story's chief hero.

And many miss this point, including Peter Jackson, as well as George Martin apparently.

George makes a good point-- with regard to the movies; since they make Saruman into a petty character, and the story could have done fine without him.

In the book, however, Saruman-- not Sauron-- is the chief villain; and indeed he wants the Ring for himself, not Sauron; and his treachery was the only reason that Sauron ever came to power in the first place, after Isildur defeats him.

So Saruman's betrayal is the center of the entire story-conflict, for many centuries-- ultimately causing Gandalf's death, by forcing him to go through Moria instead of Rohan.

George Martin, however, should have understood the book better, than did Peter Jackson; who apparently thought Saruman just decided to become Sauron's servant, despite being charged with destroying him.

In the book, Saruman pretended to ally with Sauron, to learn his secrets, and ultimately use them against him; but he also wanted the Ring for himself, to rule the world with it-- and under no circumstances would he have helped Sauron get it.

In the film, meanwhile, we're giving conflicting messages about the Ring; saying both that they lack the ability to use it, and that it would make them too powerful.

So why would Saruman not want to become super-powerful himself?

That's the film's entire failing-- i.e. we're told that Saruman lacks the ability to use the Ring.

But that's no reason why he'd want Sauron to have it; since the Ring only existed, because Saruman refused to destroy it long before when he had the chance, wanting it for himself.

Which wouldn't make sense, if he couldn't use it.

So the film's biggest mistake, replacing Saruman with Sauron as the chief villain.

Because in the book, Gandalf returns because of Saruman's treachery, to take his place as the chief wizard; and when he appears in Fangorn Forest, he tells Aragorn that in a sense he is Saruman, "as he should have been."

In short, Eru made an exception, because Saruman had deliberately sabotaged the entire mission.