He asks questions: "why do people...?"
I don't know (or maybe I do), but I can tell you that my diverse group of queer & disabled friends don't act like that. Actually, we've specifically, consciously chosen not to.
It's one thing to be frustrated about people behaving in damaging ways & building cultures of destruction around themselves. It's another to write off people as a whole because you won't take the trouble to find other people living other ways.