And I have been told that no matter how precious the lives you were protecting were to you, killing someone isn't a memory you want in your head. Either it will bother you forever, or worse, you'll find you liked it, and that changes you.
Had the situation had been different, say I was alone and it was merely a robbery by some kid or something, sure, I would feel differently if I killed them (and I wouldn't). I just don't accept the initial premise of your statement for my experience and those I have spoken to in similar situations.
Edit: also why is the other post expressing the same sentiment dead? Along with all the other posts by that person? The part about banning healthy violence resonates with me. Young people fight, young animals fight, if it doesn't cause permanent damage it is a healthy part of learning how to relate to each other. And if non lethal violence was less taboo I suspect letha violence would be less common.
He got banned somewhere around here: https://news.ycombinator.com/threads?id=iwillbenice&next=334.... The account name (and the fact there was no mod warning post) makes me think that wasn't the first time.
Though I suppose seeing the people you care about getting killed or injured also "isn't a memory you want in your head," either. Seems like a damned if you do, damned if you don't kind of situation.