As Robert Heinlein pointed out, "Women and Children First" isn't JUST being nice, it's basic species survival. Same reason you use men and not women as line combat troops, even though since guns came into use, size and strength are not as significant for combat.

If a tribe loses most of its children, and its women of childbearing age, the tribe will probably die out, unless the men can steal more women. If the tribe loses most of its men, but the women and girls are largely ok, the tribe as a whole can survive if the few remaining men and older boys are willing to work really hard to make it survive, if you catch my drift. I think that logic still operates at some level, even though our society functions at above a tribal level, part of the time at least.

Peter