There are two others, Steven Barnes and (the late) Octavia Butler. Besides being great storytellers, Butler won the MacArthur Prize and Steve has written episodes for a variety of TV shows over the years. Each was (arguably) commercially more successful than Delany. If Butler were still living I'm sure she'd have been interviewed as well.

It's interesting that despite the phrase "...the face that stared back was as Negroid as my own.." in one of his short stories, it didn't occur to me that he was black until reading it in some interview or something. If I gave the line any thought at all, I probably dismissed it as poetic license or something.

Walter Mosley writes a fair amount of science fiction and fantasy, as well as his perhaps better known and more commercially successful mysteries.