This a very good point, but I don't really buy it. Bane seemed to be just a pawn in a frivolous revenge tirade, and was abiding by Talia's orders to wreck Gotham as much as he can. There was no real deep sociopolitical angle to his prerogative other then messing with Batman. All I just took from Bane's plan is that he wanted to fulfill "Ra's Al Ghu's destiny." Which makes little sense for me. Maybe it makes sense to you but for me I just feel it's more a hackneyed way to tread back to the first film and bring it full circle. You have a modicum of a point in with regards to the Dent act motivating the police to act in a more fascist manner, which could be one of justification for why League's at it again, but the film doesn't really spotlight what your saying or portray it in any manner which would immediately ring that to mind.
Granted, the film by itself is certainly flawed. My analysis was based more on the whole trilogy, what was established about the League and its mission in Begins
. To the extent that TDKR works at all (in any portion where Selina isn't the focus), it's as a continuation of what came before. It doesn't stand on its own as well as TDK does.