Originally Posted by FeedOnATreeFrog
The reasons why they want to destroy a peaceful city are fan-fiction?
The answer that the movie gave was that despite the extermination of organized crime (mob), Gotham (and perhaps all of the West, in the eyes of the League) was still (or perhaps increasingly) full of white-collar corruption, giving way to large wealth gaps, high unemployment, etc.
I'll watch it again, but my memory tempts me to say this is an exaggeration of the material the film actually provides.
If you can cite me the exact moments these things are explained, I'll be able to watch for them when I pop the Blu-ray in soon.