After all, there's plenty of bad stuff out there. Inevitably, in any writing, fiction or nonfiction, there's more bad stuff than good. Books like these will at least give the new reader a chance to see what's good out there. And most of the writers who have short stories in these anthologies have also written novels. There is, in spite of everything, a lot of good reading out there.
Good stories are good stories, no matter how they're categorized.