It doesn't sound like you have spent much time in the DMs seat. Having clear rules makes running the game easier. The rules can't cover everything that pops into a player's mind to attempt in a session, but they should cover the obvious things. Rulings over rules is the concept that a DM should be able to come up with something on the fly when nessasary to cover corner cases, and to add the need flexibility to a system that can't cover everything. It's not an excuse to allow lazy game design. D&D is a game, and there should be a strong enough ruleset to properly the DM. If the rules aren't where they should be it just creates extra work for the dm.

What he is saying is that he would rather take personal time away from the game session to learn a heavier ruleset then to have to bog down actual game time making rulings on things that should have been made clear in the rules to begin with. That Is not wasting everyone's time. That is using your own time to help avoid wasting everyone's time when the game is being played. I don't believe the author is the dense one in this scenario.

100% accurate. Paying that much money for an incomplete system, with tons of holes in the rules is ridiculous. Having the option to homebrew and make adjustments based on your campaign is fine. Having to house rule, often on the fly, in order to just make the game function at the table is not. It's great that 5e brought so many people into the hobby, and that it's easy to learn. It's nice to have a gateway product like that, but overall it's not a very good game. It's a terrible version of D&D. They have made it so corporatized, and vanilla to make it appeal to the masses that it's just a hollow shell of the game it was. The new books are pushed even more in that direction. The best advice is use it short term to teach new players what an RPG is and then introduce them to good RPGs.