One thing that I keep seeing coming up over and over again in these discussions is a wide assortment of variations on this complaint:
"So, all storytellers should shut up because they can never tell everyone's story for them, correctly and exactly as that person would tell it, if they could? And we shouldn't even try, because we'll only Get It Wrong?"
"I'm a white male, and this suggests that I'm not allowed to write anything but white males."
... and so forth.
My knee-jerk reaction is "Right, because it's all about you, buddy; way to derail the conversation. Stuff it and grow up." But I remember that not too long ago, when I first started doing a lot of reading about cultural appropriation, I ended up tying myself up in creativity-stifling knots because of precisely that fallacy. I still go through regular fits of guilt-ridden "Am I doing this right? Should I be writing about this at all? AAAUUUUUGH" (though I seem to mostly manage to keep it to myself or channel it into actual, constructive questions to ask people).
I get the general, maybe unfair impression that most (white) writers who post that sort of comment are afraid not of actually screwing up what they write, but of being unfairly accused of doing so. It's like saying "I can't write about space travel! People will accuse me of knowing nothing about physics!" Bzuh? X does not imply Y, at least not if you do your research and don't write such a rushed hack job that it's blatantly obvious that, yeah, you really don't know anything about physics and can't be bothered to learn ... in which case you kinda deserve to be taken to task for it.
That's a frivolous comparison, though, because it's much less important to get your physics right than to try not to screw up when you're writing about people's lives, people's identities. You're not going to break someone's heart if you misremember the Planck constant. And yet people research the hell out of their physics, and then turn around and half-ass the most fundamental aspects of their cultural research, if they bother to research at all and don't just base their "other" characters on media stereotypes, or leave them out entirely. The bookstore shelves in the SF/fantasy section are groaning under the weight of generic Eurofantasy, and science fiction with all-white main casts and stereotyped, flat, undeveloped, ultimately doomed characters of color. And still you have a lot of white writers complaining that, when it comes to writing characters who aren't like them, they're damned if they do, damned if they don't.
Well ... yeah. We all are. Because we've all got the weight of history on us -- the things that we, as a society, have done over the years, and the stories we've told ourselves to explain what we did. And all of that, all together -- it's heavy. It weighs heavier on some, pressing them down and crushing them flat; on others, it's so deceptively light we can ignore it and ignore people who complain about it. We can pretend it isn't there, waving it aside because it's inconvenient or uncomfortable, but whenever we write anything, that history is there, invisible, pressing down, no matter how much we try to pretend it's not. It influences how we write race (and gender, disability, sexuality); it influences how our readers are going to respond to it. Unfair? Yeah, it really, really is. Wouldn't it be great if nobody had to worry about it? Wouldn't it be awesome if we could make it go away? But it's there, pushing our hands towards certain keys on the keyboard, quietly guiding our minds down well-worn tracks that lead to the same tired old stereotypes and cliches. You can ignore all of that and stay within your comfort zone and only write what makes you comfortable -- and that is a loaded, political choice, too. Everything that we do (when we're writing, or just going about our daily lives) is loaded with meaning; it all takes place within that historical, cultural framework. There's no way to separate it out, no way to write in a cultural vacuum, or to expect your readers not to be towing the same massive barge of historical baggage that you yourself were dragging when you wrote the thing in the first place.
You want to get angry at someone -- don't get mad at the people who are doing the hard and thankless work of pointing out the places where history is still fucking us over. Get angry at the ones who did it to us instead. Get angry at all the atrocities and the genocides and all the nasty little lies that we told ourselves to justify it -- all the many ways that we wove our self-justifications into popular entertainment until we, as a society, created a whole rogues' gallery of cruel caricatures that still spring up on the written page whenever we relax and stop watching out for them.
Maybe if we can get angry enough, we can push back hard enough against the weight of history to give ourselves the breathing room to tell different stories, better ones, until eventually the old narratives are pushed aside as they deserve to be.