The comics have never been about hard hitting social commentary or deep psychological analysis (no matter what grown-up comics fans with too much time on their hand read "between-the-lines"). It's just all about some super detective, with a questionnable fashion sense, who kicks the butts of some villains, who also happen to have a quite puzzling fetish for tacky, garish and gimmicky outfits.
I don't know why people always expect the translation of by-the-book comics characters and mythos to the silver screen must imply some sort of "serious" take on the character development and a strong emphasis on deep, quality and believable story...
And this whole "I grew-up with [some comics character], so I'm enjoying seeing him evolve into something more mature" phenomenon rings no bell in me. I understand it, from a social and psychological point of view, but it's definitely not on my line of thoughts. Some people love the Dark Knight from Miller, but personally all I see is some awkward and watered down mature take on the Batman character.
Why awkward and watered down? Because for me to take the Batman character seriously, you'd have to depict him as plain bat-shit insane (pun obviously intended). Only a completely crazy character, who would be filthy rich, would dress as a bat and do what he'd consider vigilante work. And in this case, it would be impossible for him to be a good-doer, or be surrounded by other maniacs, who also dress crazy, but happen to be his ennemies. A "serious" take on Batman would be the story of a visibly mentally instable billionnaire, who thinks he has to serve quick and very violent justice for some crazy reasons, if not homicidal and bloodthirsty motives. No good-doer stuff, no friendliness with the authority, no kid friendly character, just a crazy billionnaire who will try to get away with murders of people he and only he deemed guilty of capital punishment. But you know what? That would kill the Batman franchise, and the end result might just as well be a disappointing adult-themed graphic novel or movie.