Ok first off I find that first line of text questioning whether they are sexist or not is very off key, just because there are no female soldiers available to play as does not make the creators sexist nor does it say that they don't want women to play the game.
If you're really keen on playing as a female I suggest that you go play the free games War Rock and Combat arms.
For THREE Reasons ONE You Get To Play As A Female And Two You're Not Going To Be Playing A Game Whose Creators you Question To Be Sexist And Thirdly It's Free.
YOU WIN THREE TIMES OVER
I'm not being rude I'm saying this in all honesty that I'm Being straight with you.