To be honest, I didn't expect to find even *this* many female WC fans. I know this is a stereotype, but it really does seem true - that women are more likely to be attracted to cute or non-violent things.
Take Ragnarok Online, f'instance - it's got a larger group of femplayers (and not to mention a massive group of crossdressers) compared to the WC community, because they're attracted to the cutsey graphics and (usually) bright, cheery feel (Not to mention the pet system). Guys still play the game because it's an MMORPG at its core (... and not to mention that female classes, in general, wear next to nothing).
Comparing that to Wing Commander, there isn't really much for them to get excited about. Except maybe the fluffy kitties in space ships bent on the destruction of the human race. I guess it goes back to that study they did about kids and toys - when put in a room with action figures and baby dolls, most girls will go for the latter and most guys will go for the former...