It's generally a big no-no to differentiate genders in computer games. It's a game mechanic, so the player has the opportunity to roleplay without having to be "punished" in-game due to the gender they choose.
Yeah, that is WHY you should be punished, "Err I wish to roleplay a woman and help a faction who uses and enslaves women" you role play in a pre set world, the world tells you women are cattle to the legion and as such you should be cattle... this isn't a spoiler because I have no idea but if I finish the game and don't get beaten over the head and chained up for not knowing my place something is definitely wrong, I played a female character just to see if they did the right thing by this