What I think? I think there’s two issues at work.
1. Black writers write about black people and experience and they have difficulty getting published or reviewed. Non black writers “go” black and Boom! Bestseller.
2. When white writers write black characters you can’t buy it because it’s wrong or flat or insulting or one dimensonal. And no one likes to be misunderstood, especially in the context of number 1 occuring and you can’t get in the door, while number 2 is occuring.
That’s a rage factory at maximum output.
I’m not going to go all Kulturgeschicte and explain too much. No one needs that. But if white authors don’t engage, and engage properly, then we get Girls, season 1. And Dunham said amid the hubbub that she didn’t write in Black characters because she lacked the specificity of that experience (i.e. no black friends, don’t have time to learn.) The result of her following her presciption is no black characters at all until a furor is raised and then a black republican character for 1 episode of season 2. Furher separation doesn’t seem like a good idea. What’s the answer, I don’t know.
But identifying such a complex question is probably a good first step.