There's a current series of posts going 'round on the topic of cultural appropriation (something I think about a lot in regards to my own often-flawed attempts to write multicultural worlds). It begins here with Elizabeth Bear aka matociquala's post on writing the "other" in speculative fiction. Then there is an open letter to Elizabeth Bear at Seeking Avalon, pointing out a problematic character in one of Bear's novels as symptomatic of the larger problem of poor representation of characters of color in SF. And, spawned off a comment thread in Bear's LJ, there is I Didn't Dream of Dragons by deepad which is, really, one of the best posts on the pain and harm of cultural appropriation and lack of representation in mainstream Western fiction that I've read. Then Elizabeth Bear responds to the "open letter" post in a way that is more open-minded than defensive, though that doesn't stop (white) people from getting defensive all over her comments. And shewhohashope has an insightful post about that defensive response. (These posts, and the comments to them, have a few more links as well.)
I think deepad's post resonates for me in particular because it strikes to the heart of why I spend so much time thinking about this, and reading about it, and trying to fix the places where I've messed up and to mess up less on each project I try. Because when you don't do that -- when you write about universes peopled exclusively by white straight men, when you play at "diversity" by sticking a few token and stereotypical characters into the mix, when you ignore readers who tell you "Hey, you screwed up here" -- you hurt people. And I don't want to do that.
In a broader sense, of course, I write what is interesting to me. I want to write about a multi-cultural, multi-ethnic, sexually diverse future because it's a fascinating place and because it's the way I think things are going to be; because the people I know are not a cultural, religious, ethnic, sexual-orientation monolith and I want to write about that, too. And I know that I haven't done the best job (to say the least) of depicting the diverse world I envision; in "Raven's Children", especially, I know that I messed up in some pretty fundamental ways, and Kismet is not without its share of problems as well. But I'm trying to fix my problems, and do better, because I want to write my escapist fantasies without having them be a poke in the eye to anyone else.