If we're positing that the white male authors you submit ostensibly sit at the top of the genre according to its proponents, and I don't disagree with those names on the whole, which of those authors is nasty, vicious, or depressing?

Foster Wallace, Chabon, DeLillo, Lethem, surely not. Roth and Updike can write depressing books, but are certainly not limited to depressing books, and I've found that even their saddest stuff reaches moments of sublime humor. The best writers of literary fiction are masters of humanistic writing.

As to what you called the secondary tier of litfic, the stuff which I would say is written FOR white women more than it's necessarily BY white women- plenty of white men also write it- I suppose that's where the depressing tag on litfic comes from. I mostly don't read those books, but I've read enough to know that some of it is worth reading and most of it probably isn't. But that's just Sturgeon's Law.

I don't intend to exclude Mieville from SFF, but then, I've always included Philip Dick on both my list of Post-Modernists and my list of SF writers, so clearly I'm not very good at this genre thing.