Are you joking? Joker and Two-Face. Duh. ;)
You are a very bad man. ;-P
It's a reflection of the individual's powerlessness in our age.
That too, but more a cultural glorification of individual courage at the expense of building functional communities. I suppose its a bit of a vicious circle-- your told you should be able to do it all on your own, but it doesn't work out too good, depression follows, then escape into a power fantasy, and if you're not thinking clearly you might take the literal message to heart. Which really sounds seductive if you're feeling that individual powerlessness.
There are more layers too--the manipulation of this medium to all but neuter any empowerment that might inspire the reader in this medium.
For instance: did you know that Batman never had a problem with lethal force in the beginning?
It wasn't until the War was over and the comics code got a hold of him that he started to be an "anti killing no matter what the circumstances" ponce. Think about what that's saying culturally--don't be effective. Please god don't be effective as an individual! Yes you can defend yourself--sort of, but not with lethal force. Ever. Cause that's bad. And you're a bad person.
That's the message a kiddie gets reading that bollocks. And if it's in direct contradiction to known reality--dangerous hood, abuse, or they have a parent whose a cop-- it does a number on their heads. In real life most people who might be attacked do not have overwhelming physical strength to take everyone down non-lethally. (Yes, killing, even unarmed,is easier than capture).
Superheros started as a way of building up the mystique of personal courage in a culture at war. Once the war was over, the stories didn't go away. So they had to be controlled and re framed--don't want kiddies to get ideas that will upset the apple cart.
So Superman--never mind he's an alien and has the power to single handedly stop any genocide he wanted to--we'll make him so American his identity will neutralize actions against US interests no matter how evil. And we don't let our writers go there. Ever.
Suppose that's one of the factors that made Spiderman popular--his powers are not overwhelming and he has no hesitation to "misbehave" if it helps people. Mind, I'm sure the writers are kept on a short leash...