Forcing out the worst in people, with the whole world watching, would be in line with League philosophy. The people that rallied to Bane's side weren't exclusively Blackgate inmates, either. Recall that he'd been taking in at-risk orphans and people who couldn't find work in Gotham. So, by giving these disenfranchised Gothamites the option to strike back against the corruption in their bureacracy, Bane and Talia managed to show the world the darker side of Gotham: seething anger in the masses created by a system rife with rot. In essence, this is an upgrade on what Ra's intended to do with Crane's toxin (as far as a city tearing itself apart goes). Bane outright states "I am the League of Shadows," which is self-explanatory. Bane going with option C isn't that farfetched when you consider how he reacted when Bruce reminded him that he was "excommunicated from a gang of psychopaths."
I won't argue about Talia's ignorance to her father's philosophy, though.
Same time next week, gents?