I'm a huge fan of superheroes. They are the modern day mythology, and can be a good metaphor of abusing power, especially in the modern world saturated with weapons of mass destruction. They are the ultimate fictional escape. So close to our time and reality yet so detached.
Superhero movies are not as good their comic book counterparts, but they are getting mighty close. I've just seen the Avengers. I HAD A BLAST WATCHING IT!
The modern technology of movie-making and serious direction comic book superheroes are taking, we could expect even greater quality of superhero movies. And when the time comes for the Justice League movie...I will hold my fingers and hope they do it right, since it's my big desire to see them on the silver screen.
I think you underestimate the narrative power of comic books. Have you read Watchmen, or any of the legendary graphic novels?