i can see how you'd think that, if your completely void of imagination.
Surely.
If you can find me story that will translate on film, to the epic scape which a movie like TDK requires, then I will accept that. Simply put, as far as I'm concerned, there are great Batman stories told that aren't necesarily "city in peril" type stories, but on paper those stories lack dimension. The Killing Joke is a fantastic grpahic novel, but even if extended, it wouldn't make a great Batman movie because the scope of it isn't great enough. It's a Batman vs. Joker story, where you delve into the psychosis of the chracters. Its fantastic, but a movie it is not.
When you create a comic book movie, you are not basing it around a canon. Sure many storylines work wonderfully in the comics, but so much of that is because it belongs to a canon, where it is firmly extablished, and smaller, less important stories can be told because the scope of the character is still there, thanks the the history that surrounds it.
Hence why when one creates a film, this scope has to be incorporated entirely, so that every level of the comic reaches the audience on some level. So many elements of Batman's history will be present in TDK, but it needs to be ona truly epic scale to incorporate all of them, to invest the characters into the story.
Take Batman Begins. Sure the climax is the "city in peril" but so many of those other stories are encapsulated within the movie.
An origini, a one on one, a master vs. student, a lvoe interest etc. etc. etc.
So many of these are focuses of single comics, however to create a movie that brings all of them together, you need a backdrop large enough to paint all of them on.
So if you want to tell me I lack imagination, thats fine and dandy, however I still maintain that without a threat to the people at large, that any superhero has sworn to protect, that you cannot create a good superhero movie. A great superhero story perhaps, one that would work great in a comic, or a TV series, sure, but a movie . . . I personally doubt that very much.