Men have been constantly culled en masse so they're selected for cooperation at war. Women only failed to individually reproduce if they weren't sexually attracted to the invaders that killed the men of her tribe. This has obvious consequences.
Great, go hold trials for people dead for 4500 years. The point is that women who strenuously objected to this didn't pass on their genes and women who didn't mind as much did. We're descended from the women who either liked it or didn't care and not the others.