In nature way back when life was fragile and life expectancy was up to 30 years of age one man can impregnate several women. So if you have 5 men and 5 women equally no problem even if the rest of the men are killed leaving only one man alive the species can still reproduce. But if we reverse the roles and there are 5 men to less than 5 women, there is a lesser chance of the species to survive. It also would breed competition amongst the men for the women, maybe even leading into bloodshed. Even in war, men are targeted for termination while women are spared from termination, because of their ability to reproduce. Women already have more rights over men on this issue. The feminist movement was to get more rights and power over men. Because men and women are not created equally they cannot have equal rights. It is an unspoken wisdom that is true even if not politically correct.