I don't think it's a missing genre pre-se at least that isn't the main reason for the lack of female gamers. I think it has more to do with the attitude and tone of most games where things are still very much a macho affair in a man's world with male protagonists who have largely superficial relationships with women.
Uncharted 2 is a good example of how to do it right, apart from being an absolutely amazing game, it had strong, believable and integrated female characters who weren't just there for eye-candy. Of course for every Uncharted you have 10 gears of war or call of duties where you don't even see a female character.
It would be interesting to see stats on gender breakdowns because iirc female 'gamers' made up about 45% of the total market share for all games (casual/mobile/AAA/etc...) so ladies are playing games just maybe not that many AAA games. So maybe we are missing the gaming equivalent of a 'chick flick' but the only games I've seen that focus on the female gender have all been aimed at girls rather than women.
