Originally Posted by Victarion
Bane wasn't doing it for Ra's, so much as he broke Batman and carried out Ra's plan on a grand scake for his own benefit. When you look at Bane's reaction to Bruce's "You were excommunicated by a gang of psychopaths" and take it together with visual cues like the jacket grip Bane shared with Ra's and the full story about his time with the League, it's apparent that Bane's jealous of what Bruce had with the League. Ra's had rescued Bane and Bruce from similar circumstances, but threw out Bane in favor of Bruce. Then Bruce threw away the opportunity he'd been given by Ra's. On the side, there's Bane's line to Daggett about power that indicates he had some stake in the social revolution.
Now, if Bane tried to build a mob of followers juiced on a Nolanverse take on his classic Venom, I'd say it was more a repeat of BB.
"I am here to fulfill Ra's al Ghul's destiny!"
you can say all you want, but with Bane saying that twice in the film I am more than convinced that he was doing this for Ra's and Talia. The contrast with him and Batman is just to add some depth to their antagonism.
and I'm not saying they had to go flat out venom and mobsters in DKR, I'm sure Nolan could have came up with something great with a hispanic Bane if he wanted to go that route. I don't see venom that being such a bad idea, since he was defeated the exact same way in the comics (having his supply cut off).