I think it has been said that bruce needs to witness this as punishment. mostly egoCan someone answer this question, it really bugs me because it's a huge part of the movie (even if it's unanswered, it won't change how I felt about TDKR):
(1) Why does Bane want to start a revolution in Gotham when they're going to blow up the city anyway? Why not just detonate the nuke and finish the job?