The quote I am responding to is this, with highlights that stick out to me.
This tells me that the players are passive in their role in this game. The DM presents something and the player can provide a thumbs up or down, but no significant input. Even if the players all did fundamentally vote against the DMs idea, the DM is under no obligation to abide by it since the game is not for the players but him. It's HIS art, they are there to consume it.
That goes beyond if I can play a Tortle or not. That is a fundamental issue with the power dynamic so brazen it borders on offensive. I don't know if it was intended, but it reads like the players are there to glaze the DMs creation rather than the DM presenting something for the benefit of all the players.
They don't do collaborative world building. That doesn't mean the players don't have autonomy through their characters. That's the description of the default in D&D, DM as author of the world and the players control their characters. Players can still have plenty of autonomy, their role is simply different and their autonomy is expressed through their characters.
There's nothing "offensive" about it. D&D simply doesn't assume shared world building even if that's your preference.

