U.S. Army Special Operations Command, in a lengthy study, reported a wide range of “overtly sexist” comments from male soldiers, including a broad aversion to females serving in commando units. The comments, it said, are “not outliers” but represent a common sentiment that women don’t belong on special operations teams.
“The idea that women are equally as physically, mentally and emotionally capable to perform majority of jobs is quite frankly ridiculous,” said one male commenter. Others said they’d quit before serving on a team with a female, and that serving in such a situation it would create problems and jealousy among their wives.
There are lots of countries that have compulsory military service with alternatives for conscientious objectors (which is basically what you’re describing).
I agree that it’s a good idea. Moreover, it comes closer to the original meaning of that whole “well-regulated militia” thing. We should consider doing like the Swiss do: give (roughly) everybody mandatory firearms training, send them all home with an infantry standard-issue assault rifle, and then severely restrict access to ammunition except for legitimate purposes like practice at the firing range.