As an historian, I understand that one of the best ways of understanding nearly any aspect of a society is to understand where it comes from. Take superheroes, for instance. Throughout the world they all have some basic features. Now I don't propose to go all Joseph Campbell, but I do think there is a point to be made here.
One thing that seems to go unnoticed about superheroes is that they have superhuman abilities for their culture. So for instance Achilles was cut across his Achille's Tendon and died because the concept of total invulnerability was beyond them. And Achilles was only so protected because his mother had dipped him in the river Styx. Even gods were not beyond wounds. Diomedes managed to defeat Aphrodite and Ares in two separate fights, injuring them both. Hercules put on a cloak with poison in it, and his mortal half died. You see the Greeks could not imagine titanium or the concept that anything living was not also capable of being injured.
Second item; throughout the world heroes neutralize and/or trick the bad guys. King Arthur decapitates Urien, his most difficult personal combat. Thor kills, as does Yoshitsune and Tametamo in Japan, Roland in France, Sigurd among the Norse, and Arjun in India. In more recent myth, our own frontiersmen, gunfighters, and lawmen killed Indians, outlaws, and lawmen.
It's only in the last century or so that our heroes have attempted incarceration and have tried to save the lives of villains when possible. Despite Batman's harsh views of the world, he keeps sending the same people back the Arkham. That, too, is a function of the culture we live in. As our concepts of life and the psychology behind antisocial behavior have evolved so has what we consider proper penalties.
Finally, our superheroes represent those people in a society most able to patronize the stories. This means a culture controlled by Japanese will have heroes who are ethnically Japanese, Hebrews had Hebrew heroes, Aborigine had Aborigine heroes. The Greeks traveled the Mediterranean, but their superheroes were almost exclusively Greek (exceptions like Hector and Orion come to mind but they were clearly lesser heroes). The same goes with every culture; superheroes have traditionally been a means for one culture to prove to itself it is superior to all others. It comes as no surprise the same thing is happening with our own superheroes. The most important ones in both major comic universes, Star Wars, and Middle Earth are white and mostly male (even Mace Windu was not in the original script).
I recently read an article naming the X-Men as a forward-thinking comic because it had clearly been made with a minority in mind. They were initially intended to represent nerds and other outcasts in high school. They have evolved from that point. The clear delineation of Xavier and Magneto's philosophies strongly resemble the approaches of Martin Luther King, Jr. and Malcolm X, respectively. The point was also made that the scene where Iceman reveals his mutant abilities to his parents in X-Men 2 looked exactly like a "coming out".
The article went on to (rightly) complain that whites as a culture group were using the comic to make their own case about being discriminated against. Why? Because the majority of the mutants are white. The very fact that the comic, and most other comics, are composed primarily of white heroes negates that statement. On the contrary, it clearly shows that the white culture group is the dominant socio-economic group in the United States.
Should we have more ethnic diversity in our superheroes? Of course. Will we? Only when the dominant culture group (White, Black, Hispanic, Asian) no longer feels that it needs to use superheroes to demonstrate its superiority. That may be years, decades, or even centuries in the making. It takes less effort to enforce equality in the workplace than it does to fabricate new and different heroes for a culture.