Not really. I think it's a crueller punishment to leave them alive to get on with it. For me, it's the narcissists/ sociopaths I've known in life that I think the world would be better off without. But then, I think they tend to thrive in this world. I have a more sadistic fantasy that one day, it will only be them left. They won't have any more 'weaker' people to pick on. I get more satisfaction at imagining them having to face people just like themselves or, worse. See how they like a taste of their own medicine.