I understand your hypothesis, thank you for positing it. It seems to fit in with my question of why the violence. Why are stories with violence more appealing? Look at fiction in general: how many works of fiction in text or moving images have death and destruction as main plot elements? I understand your point about good vs. evil, which is highly salient, but why the go-to of the way to defeat evil is to get out your weapons? In the real world, violence is sometimes necessary but not usually.

My question back is how many of these video games actually have the players saving lives from evil? From what I have seen, which admittedly is not much, the players aren't being a white hat cowboy or honorable samurai saving innocent villagers from bandits, they are simply killing for the sake of wracking up points.