Something tells me that quote wouldn't hold much water if 90% of all game protagonists were gay. There'd probably be some people clamoring for game characters who catered to their straight sensibilities. Or just for the simple sake of variety.
And saying 'why can't you relate to characters whom you don't share physical characteristics with; are you a psycho' is a nice way of deflecting legitimate issues with diversity within media. Women, non-whites, and gays have pretty much had little choice but to identify with straight, white men in movies, series, and games. And very few of them ever made claims they can't relate to them, just that it would be nice for them to get some more options. That along with how stigmatized some of these groups are, so that the gay or trans character isn't depicted as the usual victim or creepy weirdo.
And the 'Dumbledore is gay and Hermione is black' issue wasn't that they needed to be, but that throughout the entire series there's zero implication of this only for Rowling to suddenly present them as such when the story was pretty much over. It comes across as her trying to be inclussive while conveniently having dodged outcry from conservatives or racists had they been so from the start. Can you imagine Dumbledore being depicted as gay starting from the first book back in 1997? A headmaster in charge of little children is gay?! This was before even the shitstorm over Spongebob and Patrick being a bit too gay for being friends and not having girlfriends.
Something tells me if 90% of game protagonists were gay, and straights were out there demanding gay characters be turned straight there would be a lot of uproar.
And its not deflecting diversity if media, its saying that audience control of the story isn't as important as the story being told the way the authors want. That quote is from the Dishonored 2 review, and Yahtzee goes out of his way to say the woman's story is the stronger, better story, and there was no need to give the choice to play as the man. That one is a natural progression of the story from the first game, and the other is for people who no sense of narrative build. Some stories are meant to be told from a single person's perspective, and changing some fundamental detail like their gender can make the story worse.
And as far as this idea that women, gays, racial minorities have been forced to identify as straight white males is, well frankly its bullshit. We've had none white male characters since like we've had writing. Books going back to when books first started weren't all white males, they didn't tell the story of John Smith public accountant from Cheshire in Ancient Egypt. The Greeks weren't well known for only having straight male heroes/Gods. Movies have had diverse leads and stories since movies first started. Same with video games. Its only popular video games from the last 2000s/2010s that sell well with straight males that do well with straight males, and some companies want to pander to that audience. Before that most game popular game characters were cartoon animals, weird monsters, genderless sprites/objects, or robots. Doesn't mean alternative don't exist, didn't exist, or aren't readily available.
As far as JK Rowling is concerned, I fully agree she's being transparently cynical with calling Dumbledore gay years after the fact to score points. Its meaningless, in no small part that Dumbledore's sexuality, to my knowledge, is never brought up once. I don't recall talk of an ex-wife, children, spouse, being a widower, nothing. What's the phrase, Chekov's Gun? Only have a detail if its going to pay off later, and seeings how Dumbledore was functionally an exposition dump and God character in the Harry Potter stories, their sexuality or lack there of wasn't important. Same with Hermionie being black and in a wheelchair. Personally I think that's a really cool change to the character I would have loved to be in there since the beginning. I think showing handicapped kids they can still be heroes, and unfortunately magic can't fix everything would have been a very powerful story element. But she didn't do that, and going back to retroactively claim so was bullshit on her part, and in no way does she deserve props or acclaim.
If she wants to be inclusive write another story with new characters, don't change already existing ones.