Personally I loved the whole "Gotham tears itself apart" angle and how cheap it felt - i think it's intended. Shows precisely why Bane was kicked out from the League of Shadows. Portrays him as one strong and brilliant motherfucker, with just a little less then good understanding of how ordinary people's minds work. Sure, the ordinary joes did some stuff and some of them seemed content with what was going on, but yeah - the majority of what happened in Gotham was Blackgate prisoners plus some of Bane's own mercenaries. When Ra's Al Ghul planned to kill Gotham in the firs movie, he didn't even really care about proving that the city is corrupt, he just wanted it to tear itself apart. Bane seemed like he wanted to make a point, but just to be sure let's release 1000 of prisoners out too.