I hadn't thought about it until now
Neither had I - certainly not really deeply. However, recently I've been reading a lot online criticising the treatment of issues such as race, gender, and sexuality in SF/F fiction.
For example, I found this viewer account about a pair of characters in the Spartacus TV series quite touching:
http://arsmarginal.wordpress.com/2012/06/29/gods-of-the-arena/
After all I'm doing this for entertainment purposes, not historical documentation
I've always obsessed about trying to put a degree of realism into what I'm writing at the moment. I'll never have something that is "real" but those little details of historical accuracy here and there I think can add to the overall authencity.
However, addressing larger social issues means having to sit down and really think on what issues to address, how to address them, and why I am addressing them so. I think it's about increasing awareness of what you're actually writing.