From this perspective, if you're not going to get enough women to form a platoon for a job because only 5% of them have the strength requirement, it's easier just to say "no women in this job".
There's logic in segregation, but most of the reason they do it is to keep women out of combat. The military lives almost completely in the shadow of Vietnam in this respect: they try to limit public criticism of the war as much as they possibly can. Hence the prohibition of photographing soldiers' coffins, hence the decision not to count enemy casualties (nothing galvanizes opposition like hard numbers such as '500,000 dead women and children,' an estimate that is probably a little high, but god only knows). US girls in their late teens/early twenties shot by insurgents is not exactly a public relations winner.
But...there's ALWAYS logic in a non-diversified workforce. No racial/sexual tension, everyone speaks with the same accent, etc. Doesn't mean the US should stand for it. The Army integrated African Americans long before it was culturally acceptible to do so. If they wanted to integrate gays and women in the same way, you bet your ass they could. Boot camp is essentially hard resetting your brain and having it rewired into what the military needs it to be. If the military says you integrate with gays and women and you don't complain about it, that's what happens.
The problem is, most jobs don't inheirently seem to involve chastity and death.
This is a terrible combination in which to introduce a small, feminine minority, due to distraction value, etc., etc., etc., good lord this has to have been gone over, historically, hundreds of times.
Of course, no one ever thought about it more than the five minutes it takes to say that.
Why military seems to have such a problem with normal relationships on job hours is a beyond me, is why I say that. Historically, people tend to protect their spouses far more strongly than anyone else besides their children; Such links should be an incredible morale booster.
And it'd be fairly simple to cut down on the distraction value downside for the rest, if people really cared, by simply utilizing legalized prostitution.
(There are other solutions, but they're just as... tacky? to most people, though, such as cash incentives to women to increase the relative amount of women, or hiring lots of homosexuals. Legalizing prostitution within a certain area of military property sounds hilarious as a solution, but honestly it's something that probably should have been done ages ago. It's not like prostitution around military bases doesn't happen; This would just make the problem
less ugly and obvious. Strikes me as a pretty elegant solution.)
The problem mostly is that the military institution is a collosal old boys club, often running in family dynasties, with literally hundreds of years of tradition, pomp, circumstance, and ultimately, calcification... and it's simply not really feasible to change it's basic workings to include women easily, currently. Kinda sad.