From a reproduction stand point, I think the males are the expendable ones because the females are the ones who really do the reproducing. One male can impregnate many females, where as a female can only be impregnated by one male at a time. So, if a society was cut down to like, 10:1 for females, the population could continue to grow rather rapidly, whereas if it were 10:1 for males, it could only grow as fast as the women could birth the children.
Though, most societies value men above women for generally being the stronger sex, and the one to pass on the bloodline, honor and family name.