When I hear arguments like "Women aren't (and haven't been, historically) in the infantry; that's why they shouldn't be allowed to be in the infantry" or "The infantry won't work with women in its ranks because women aren't in its ranks now and the infantry works" I'm left contemplating the mind bending circularity of such arguments; indeed, like all faulty arguments, these two, perhaps the most commonly seen, leave a lot left unsaid given that they're so circular.
One interesting thing about the MPs, aside from the fact that I always just thought of them as cops (teenage pot smoking cuts deep into the psyche I suppose), was that there were a few female MPs assigned to the camp. So, even though there was a platoon minus of MPs, the unit was required to work together with two or three females (one of whom was actually a medic if I recall), which meant shared latrines, the existence of feminine hygiene products, and all the things that go into having women and men work together in close quarters--such as paying attention to POSH.
It's hard to debate a group of combat infantrymen on the question of whether or not women should be allowed to enter their ranks. Apparently, having credibility to weigh in on a moral issue only comes after having been an infantryman--at least to some people out there.