The greatest virtue is stability, and maintaining a similarity to how things are in the world we're familiar with.

Heroes treat symptoms, which maintains status quo. Villains change the material conditions that are the direct cause of the symptoms, which threatens the status quo.

Status Quo propaganda at play, everything is okay and only is not okay when someone EVIL tries to destroy our flawed society, that's still the best we have anyway and you can't fix it. And if you try to fix it we will kill you, because you want to destroy it.

This is kind of tangential to traditional superhero media, but this fact is the point of tension superhero role-playing games.

Most other genres allow your protagonists to play a proactive or reactive role.

Your D&D adventuring party might be trying to stop an evil plot to end the world, but they could just as easily be searching for treasures in ancient ruins primarily for personal advancement.

Your Vampire the Whichever coterie might be trying to avoid the anger of any of the elder vampires in your city, but they could just as easily be scheming to overthrow and replace those elders.

Your circle of Exalted might be hunting down reincarnating demon kings when they pop up in your corner of the world, or they may be forging a bronze age empire with modern social norms because bronze age social norms completely suck.

Your Stars Without Numbers/Trinity Continuum psychic space people could be solving a futuristic murder or they could just as easily be exploring strange new worlds and deliberately making first contact with strange alien species.

If you're playing a superhero game, and you're playing heroes, what do you do? Foil the supervillains plots. If you have your own plots? You're the villain. (One possible counter example is an X-Men type setting with persecuted superhumans, but honestly you still have to diverge from source material a lot here- mutants should be organizing violent resistance groups but the ones who do are Evil Mutants)

It's very constraining and stops more sandbox type playstyles from being viable.

Obviously "people who want to change society are fundamentally bad" is a very corrosive message to marinate your populous in, and that's worse, but the rpg thing is also annoying.

I've discussed something similar with the lib I know, that many of America's rivals are literally minding their own business and we're the ones going out of our way to cause problems with them.