The Dent Act IS what I'm talking about when I say the arguments to rationalize what Bruce did fall flat. If you analyze the Dent Act and the events in both movies, you can see why it just doesn't work and why it wouldn't keep Bruce away from being Batman. Here are my two cents on why Batman quitting because of the Dent Act doesn't work:
1) It's a complete "deus ex machina" act. There is no such thing as an act that can eliminate organized crime, let alone cut down crime rates to small criminal stuff the police can easily take care of. Even New York in the 70's, which was almost as bad as Gotham in terms of crime and corruption, still hasn't fully fixed itself to the point where you can have low crime rates the police can easily take care of. The act maybe would have been ok in a different movie but for Nolan's realistic setting, it doesn't work. It would be about as effective as a bill that illegalizes prostitution and the marijuana industry - meaning they're not too effective since people still have easy access to both those things without getting caught.
2) Even if it would work, the act doesn't put an end to all crime. It just puts an end to organized crime, which means there are still TONS of criminals out there to be caught. Unorganized crime can sometimes be even more chaotic than organized crime because there is no one to hold Gotham's criminals by a "leash" and tell them where and when to act. They would need Batman more than ever if organized crime falls.
I know this is a week old, but the only real reason the Dent Act works and reduces an already reduced organized crime (in TDK they're all afraid of the Batman, so they even hold meetings in the daytime) is because it's essentially indefinite detention without bail. So any criminal arrested once remains in jail. That's essentially what is said at the beginning of the movie.
My only real problem with TDKR is that it didn't go far enough. Seemed to approach bigger stakes, more grave situation, but stopped short. Bane for example. Dude was a terrorist, but he made a couple explosions and that's it. Threatened about blowing up a nuke. Nuke are overrated, and overused 90s story lines. Leveling the city would have been more devastating and much easier for Bane to pull off. There should have been an active resistance movement in Gotham. It should have been a warzone, quite literally. Letting criminals out of Blackgate was stupid too. He talked about liberating the people, but his audience was only the criminals in the prison. Then he gives them AKs and lets them loose. The people weren't the ones uprising like the French Revolution, which was supposedly the inspiration for TDKR.
If any one thing I like about Nolan's The Dark Knight Trilogy that I'd want any Batman reboot to emulate, it's the realistic look and feel of it. The Batman's choice of suit (military-esque armor plating) makes sense. Wearing a costume with no armor isn't smart. The suit, while maybe too busy, was practical. The voice, while disliked by most, made sense also. Why would Bruce talk in the same voice and give himself away? The awful voice helped to mask his true identity. It's the whole Superman issue. Realistically, glasses are a very poor disguise. Anyone should be able to tell that Superman is Clark Kent. With Batman, his voice would give that away if he didn't make it raspy. So I think that any new Batman should wear armor and mask his voice. The voice can be better done (maybe just deeper). The armor can be more streamlined, maybe flatter, closer fitting to the body, and less gaps between armor plates, but it still needs to be armor. They can't return to Schumaker... Can't go back to those Batman movies. Can't go back to Adam West... It's got to be a realistic looking and feeling Gotham and Batman. Even with superpowered villains, they can still be set in a world that
looks realistic, a world that functions like a real world (a world that isn't
used to or
comfortable with superheros).