Why doesn't Bane just detonate the bomb?

Question

Why does Bane talk about giving Gotham to the people if he intends to blow it all up. Why doesn't he just detonate the bomb right away?

Answer 1

He explains this best when he first imprisons Bruce as an homage to the prison where he came from.

He explains to Bruce that he wants him to watch the city struggle on while being held under Bane's martial law. Suffering, hoping that Batman will come to save them or anyone, for that matter.

All the while, he imagines Bruce just laying in his prison, suffering from his injury, watching the city die, until it finally exploded from the core, decimating Bruce's soul. At this point, Bane plans on having Bruce killed, knowing he failed 12 million people all while he just layed in a prison cell, not being able to do anything to stop it.

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Of course, as we learn towards the end of the movie, the whole point of the bomb is actually Talia's doing, in order to make Bruce suffer and garner her vengeance for the murder of her father.

Answer 2

He doesn't detonate the bomb for two reasons. First, Bane explains that true torture comes from hope. This is the function of the hole they can climb to try to escape in the prison. When there is no hope, total despair overcomes people and nothing more can torture them when they have given up completely. If there is a perpetual reminder of escape, then hope keeps people suffering. Bane wanted to truly torture Gotham, with the hope that they might survive. Second, Bane wanted to punish Bruce for betraying Ra's and the League by making him watch Gotham's suffering. This was to break Bruce by showing him how he failed the entire city he betrayed the League for.