Look at how the teacher's brain is turned off I this video. She's not thinking about the correctness of this action, only about how to do it. She's just following orders, if you asked her, she'd talk about her actions as if she had no choice in the matter, using words like "have to" rather than "should", wording that distances herself from moral culpability for her actions. This kind of person needs to die out, and the only way to do that is to kill them, line them up and shoot for the brain. These things are clearly lacking in minds or souls, do its not like killing, more like scrapping a defective device that is too dangerous to be kept around. I always used to say that the world being full of mindless idiots is terrifying because all an evil person needs to do to create an atrocity is simply take control of these sorts of creatures. We have finally gotten to the point in history where the npc and the zombie are dangerous, where their stupidity, incuriousity, apathy, and laziness are placing everyone whose actually deserving of the title "person" at risk. We must kill them, for the sake of the future, they must die.