Until recently, when I thought about diversity in speculative fiction, I thought about people. Characters, authors, and readers. Then I discovered Martha Wells' list of fantasy books by women with settings that aren't vaguely medieval Europe-y (via Book Smugglers). Or as she calls it "Fantasy by Women who Broke Away from Europe." And that has me thinking about place.
Certainly, thanks partly to Tolkein and partly to Dungeons and Dragons, the majority of fantasy novels take place in quasi-Nordic, Celtic, or Medieval European settings. The fact that science fiction and fantasy books are largely populated by white people is obviously related. However, focusing on setting rather than character opens up new critical approaches.