One thing that I see come up quite a bit online is a disagreement over how much setting control is appropriate for a DM to exercise.
Weird. I guess 5e & AL staying in the Realms is at odds a bit with it's DM Empowerment...?
So, lets instead look at it this way. How do you feel about playing D&D with a World-Building DM?
Fine. And I've played in some pretty out-there original worlds.
Would you enjoy playing a character in Westeros, DMed/GMed by George R. R. Martin? A character in Middle-Earth DMed/GMed by J. R. R. Tolkien?
(Assuming the latter is alive for the sake of argument) Probably not: DM and author are surprisingly different skills.
Would you ask to play a cat-person or a wookie, or a kender? Would you ask them to redefine who could and could not use magic?
None of those much appeal to me. But, for the sake of argument, in a setting like Westeros, part of a much larger world that has lots of unexplored/undeveloped regions, one could well make a case for some oddball race or culture or magically-talented member of a not-normally-magically-talented race/whatever coming from one of those mysterious regions.
If you're a DM and you leave a lot of your world undefined or mysterious, you're prettymuch begging for that kind of thing, but, if you're an author, you're just creating a tone & feel. Creating for active participants is different than creating for an audience. A blank space on the map of a fictional world is mystery, and the author decides when it's addressed. A blank space on a campaign setting map might get explored almost immediately, or completely ignored.
Replace those examples with any fantasy world you really like, and think about it.
Tekumel run by MAR Barker (when he was alive), that was supposed to be pretty awesome by all accounts.
I’m guessing the vast majority of people, if invited to play in such a situation, would gladly fit their character into the parameters.
Celebrity would have a lot to do with it in that sort of hypothetical.
Why not be willing to fit into another DM’s world in the same way?
Because he's not a celebrity? Because you're not familiar with the world? Because the available options don't appeal to you?
Does your answer depend on whether the world was created with you (or your group) as a player as the intended audience, vs whether the world was already existing or created for a general audience of players beyond your group?
Not really. Whatever the intended audience, the world might be interesting and inspire character ideas - or not.
My gut tells me that the objections are, at their heart, more about believing the DM just isn’t going to create a very good world (or at least one you will like) than they are power-struggle issues.
Part of the issue could just be the focus of the game. If the focus of the game is the world, that's a very different play experience than if the focus is the characters or the story or even just the overcoming of challenges.