The problem with the code is that it costs more lives than it saves. A Punisher-style kill-'em-all approach isn't necessary, but those who have proven that they cannot be contained and cannot be reformed have it coming.
I also think there's a logical jump that a willingness to use lethal force makes one not a hero. We accept it in almost every other type of heroic figure except for superheroes. Jedi kill (if reluctantly, which is how I think superheroes should be), the Fellowship of the Ring and their allies killed innumerable sentient beings over the course of their journey, but somehow having tights and a cape changes the rules? I don't follow.
There also seems to be a strange distinction between "superhero" and "vigilante" in the Viner community. Unless a superhero operates with expressed government sanction under the rule of law, they are, by definition, a vigilante. As Batman put it in the Dark Knight Returns "Of course we're criminals."
Superheroes are first and foremost about protecting the innocent. By failing to kill genocidal maniacs who can escape imprisonment at will, superheroes are allowing all of their future victims to die. And for what? For some sense of moral superiority? That's a very selfish brand of superhero; the sort who sacrifices the lives of the people they've sworn to protect to their own self-image.
I agree with this. I love Thor's abilities, they're unique and awesome, but just as much a reason I like him is his personality, look and mythology. Even if he does job sometimes, Thor has shown some pretty amazing feats over the years anyway.
This, His new title is the best Marvel Now anyways!