The human male is one of the most fucked up creatures that ever walked on the surface of this planet. It is perhaps the only creature that inflicts suffering and kills just for the heck of it, to feel good about his worthless self, rather than to survive. I think human females are much different in this respect - they inflict pain and suffering too, but by emotional manipulation, which is not as deadly as killing and gives the target a chance. If they kill, they usually do it for survival (just as most of other species) or because of confusion. For that reason, exterminating violent males makes more sense than exterminating females who committed acts of violence - because the likelihood of male repeating his violent behavior is much greater.
Wojtek