Why did the League of Shadows want to destroy a peaceful city?
I'm a fan of TDKR but the biggest gripe I have is a serious issue with the film. In Batman Begins, it is clear that Gotham is corrupt and both Batman and Raas take different ideological approaches to the corruption. Batman thinks it can be saved. Raas believes it is for the good of the world to allow Gotham to perish as it is beyond saving.
Fast forward 8 years or so later. Batman was right. He managed to manipulate the system and work with Gordon and Dent to make a peaceful Gotham. It required Batmans sacrifice but it demonstrated Gotham was not beyond saving.
So, why is it the reformed League of Shadows cares to destroy Gotham? The film toys with the idea that there is still evil below the surface. But this evil is the League itself. The film also toys with the idea that Talia and Bane want vengeance for Raas death. But vengeance means destroying an entire city of people who didn't have anything to do with his death?
My biggest gripe with the film. Would welcome a rational explanation for what motivates the primary villains to want to kill millions of people.