And the men who dropped a nuclear weapon on the superbeings rampaging across Kansas clearly felt differently. Had the battle spilled into a civilian population centre the casuatlites would be been astronomical. That's is your tough call right there.
The story ends with the understanding that incaceration and rehabilitation are not the same thing. Sure, we could kill all the villains. Then we should probably kill all the other repeat offenders. People will probably object of course - that's okay, we can just do away with the democratic process. Just suspend it mind you, til we get things sorted out. But there's so much to do, and things are working so well now. Is it really necessary to give people a choice? It's a curse, really, and you just know given time they'll muck it up. Human beings are happier when they have a strong hand in charge telling them what right and wrong is. Yes, the heroes should be in charge, ruling things and not having people questioning them.
Having a small group of all powerful beings who are answerable to nobody is the way to go. Free will just gets in the way.