Re: TDKR SPOILERS (read at your own risk) - Part 5
I can think of several reasons he'd want to lost his Bruce Wayne identity.
For one he can't be sure that no one else could ever find out or already knows that he was Batman. And he still has a lot of powerful enemies. This protects Alfred and Selina to some extent.
another is he won't be hounded by paparazzi. he can live pretty normally as long as he keeps a low profile.