Nothing to do with that really, considering Shepard's looks can be changed by the player regardless of the chosen gender. I will say however, that Western developers choose the bald male look simply because it's easier to render on screen.
A lot of guys who like playing as female Shepard (or prefer female avatars in general) do so because they'd rather see a female figure if they're going to spend all that time as that character. Personally, I choose the default look simply because all the customized Shepards I've seen, male and female, look ridiculous to me.
By the way, I'm not sure if this has been reported here already, but surprise!
There's going to be a Mass Effect anime—a feature film, to be exact. (There's also one for Dragon Age too...)