TF2 is also composed of blatant caricatures of various cultures. Scout is a New Yorker / Jersey type, Engineer is from Texas, Sniper is an Australian, Medic is a mad German Scientist, etc. etc. Its not even subtle about it.
I dare say, if TF2 tried to make a female character, it would have to be sexist as all hell just to fit in with the "feel" of the game.