it makes no sense to me, in today's day and age that you wouldn't add just 1 female model. being a female gamer id rather a female model.
Unfortunately, despite the lack of work required to make the actual models, Splash Damage saw fit to be sixist and leave women out of a war game even though women enlist in the military and police forces a lot these days. They probably want women to stay in the kitchen. I wouldn't be surprised.
Considering how surprisingly lacking in content this game is, there should have been plenty of room on the disc to handle female characters. The only REAL issue would have involved voice acting; would the disc have enough room to hold all of that audio data? Again, considering how few maps there are and the insanely short campaign mode, there should have been plenty of room.
It has been stated many times before that there are no female models. Also its a lot of work, plus no one complained when you could not toggle your gender in CoD or Battlefield.
Because those people know they can just go play Halo 3 or Halo Reach, which DO have female models and voice acting.