Actually, I think it's both interesting and inspiring to write stories about aliens, so long as you know a little bit about their lifestyles. I mean, there are a lot of alien races out there who have social issues very uncommon to humans. For example, one of my major OCs is a Dug. Anybody who's read about them in the Essential Guide knows that they're driven to indentured (sometimes penal) servitude by the heavy-handed Gran who occupied Malastare; thus this kind of issue can tell us something about prejudice and/or slavery. And the Gran side of the story can tell us something about the politics involved with a cover-up. There's a lot of stuff out there that's not easily explored with humans only, but all you gotta do is a little background reading and then let your imagination take it from there. And what, pray tell, do we writers do best?