2/2 ... and I believe it was because Ellen Pompeo was tired of the writers focusing so much in finding her a new man, so they brought her friend Scott. Which made the tasting with Hayes and the whole "Cristina sent him" and his appearance on the beach look pointless. 

Also, let's not forget how Nick pretended not to hear her and didn't talk to her for six months and later, she did the same thing, so not sure that's "healthy". I'm sure Nick wouldn't have loved Meredith in her dark and twisty era, but Derek would have loved present Meredith still for sure. 

Their relationship is not entertaining to watch, their scenes are dull, and their problems are always lame, they didn't have a good development and haven't had an interesting storyline, they don't have much chemistry either, both actors look like they don't want to be there.

Again, they are less dramatic than MerDer because they barely have scenes because they are barely on the show, and honestly, I'm glad they don't because I'm not sure I could watch them more often.

There are some reasons why most people think the first ten seasons are the best ones, and one of them is Meredith and Derek's love story.

"Her short lived relationships" were literally made because in this show apparently nobody can stay single, and Meredith being the main character of course she had to have a love interest. They kept putting her with a new man every two seasons and none of them worked, and weren't truly accepted by most fans. Ellen Pompeo said it herself, that they hurried up to find Meredith a new guy as soon as Patrick left because they believed she HAD to have a love interest. They didn´t do it with the propose of make her take "small steps" into moving on. They expected one of them would shine as much as Meredith and Derek's love story, but they didn't. She could've also had more storylines involving her own kids, they lacked of that.

With Nick it is less dramatic because they are barely there! and when they are, it's so boring, this is a drama TV show, it has to be entertaining and if Derek and Meredith hadn´t had all the drama in the early seasons, and instead would have been "less dramatic" we wouldn't be here talking about season 21 because the were a HUGE part of making the show solid. When we finally watch them become a more stable couple is not boring, it's satisfying because we had already seen them go through so much, and their marital problems were entertaining too. 

For me, her storyline with Hayes could've been a better storyline, since he had young kids too, and since they struggled to see their dad dating again, that could have been a good storyline for Meredith, and he understood her better because he had also lost the love of his life, and it would have been "fitting" as you said, because he was the one that was on the beach, but for some reason the ditched that storyline and brought Nick back...1/2