yeah, because true FPS fans would be so offended by the lack of female players, (even female games) that they will ignore the game as a whole....
It would not normally be so difficult to overlook your in-game avatar being limited in terms of six, but I'm speaking in terms of a company putting so much hype into customization and then having something so limited and concrete. There is a huge option missing here. To go out there and sell your feature as being so versatile and infinite, yet still being restricted in terms of the very basic choice of whether your character is male or female seems kind of a weird direction to take. As for the excuses they used, deferring to character animations and hit-boxes. It would make the game appear more varied if they had actually included female characters.
Let's say perhaps that instead of an all-male cast they had an all-female cast. Why was this not considered as a possibility? We are, in fact, alienating the female community. The real FPS fans that are not male might see this as more than just a simple design choice.
It's kind of like a automobile manufacturer telling you that you can pick a truck with any paint job, any added features *dvd player, mp3, etc* and when you ask for a car or an SUV they tell you that's not part of the deal.
Given the leveling up, experience and co-operative nature of this particular FPS I would actually say that it contains enough RPG elements to classify it as at least partially being one. Let's not forget the Elder Scrolls series or Fallout 3 for that matter.