Originally Posted by BatLobsterRises
But The Dark Knight doesn't give us a reason why The Joker should be so devoted to the idea of anarchy either. All we have are random lines about what people will do when the chips are down and how morality is a bad joke. Yet he's an absolute in terms of being devoted to that ideal, and we know it to be true.
But there's a difference between how the two characters are portrayed in the mythos. The Joker literally does crazy schemes all the time, because he's The Joker. It worked for the movie, and it's the way he's portrayed in different mediums, as well. Bane, on the other hand, doesn't work that way. He's not a crazed lunatic running around, he's a smart tactitioner with a more formulated plan, which we should all know, is why Nolan wanted to use Bane, because of how different they are from each other.
Comparing the two motives, or saying "one is an absolute, therefore, the other can be too", is apples and oranges....