Which normally would work, however in the comic world they keep escaping over and over again to just kill more people so then it comes down to allowing something to continue that they have the power to stop. Is it more noble to allow these villains to kill more innocent people or put a stop to them even if it damages their personal code. It tends to work better if it is a life and death battle as anyone (with sense) would do what is needed if someone is trying to kill them. Just thinking about that one animated Superman movie I saw a little while ago, the villain escaped twice and killed more innocent people, someone would need to take them out if that kept happening. They try to act like all the same world issues apply yet all these amazing things can happen.
Not being able to kill in non self defense is one thing however far too many comic writers get too preachy with the speeches, I remember this Daredevil issue where he would be willing to shot someone to stop them from killing an evil killer of innocents yet not that evil itself, too me there is no logic there. I can recall one comic with the some sicking dialog, Batman 614, I cannot believe anyone could serious write that, who thinks that way. Comics go too far the other way and have a warped sense of why someone should or should not do something.
Then the government in comics needs to amend their laws.