I described the movie when it came out as the most mature movie portrayal of a superhero possible. But despite that I mostly liked it, it ultimately came across as pretentious and silly. I also described it as typical of comics as (despite running two-plus hours) was unrelentingly serious and had absolutely no comic relief. And in that respect reprtesentative of the current pretentious/overly-serious comic book market. But again, the basic conccepts remain the same as 40-50 years ago, with some modern conventions added on. Hower dark, he's still the hero, and remains an essentially pure counterweight to the purely evil joker. I found myself wishing Osama Bin Ladin and other Al Qaida members saw the movie, so they could see in themselves the archetype of pure evil in their wanton slaughter of innocents and their total lack of regard for human life. However you try to spin it, this movie is a far cry from the anti-heroes of Garth Ennis, Warren Ellis and other modern writers. For all the dark elements, Batman remains an uncorruptable heroic icon, in the classic mold, with only superficial modern add-ons to the concept.
Joel Schumacher's entries to the Bat-franchise also retained the basic concepts of good versus evil. And guess what: they were shit. DK offered a darker, more serious and realistic spin on the same concept (one where the villain practically steals the movie) and the box office goes through the roof. So much for your theory.