An unfortunate aspect of Batman's history is that for many years, his unofficial title seemed to be 'protector of the rich people and their easily burgled mansions'. Sure, crooks robbed payrolls and museums and so forth, but it seemed like two thirds of the booty that the Joker and Co. went after was located in Mr. Vanderwhatzis's private safe in his fifteen-story manor house, or his yacht, or in the purses and round the necks of the guests attending his cleverly themed parties. Poor people seemed to be entirely ignored in the Batman books for many years, except as picturesque background detail or as a cheap bit of pathos. So it's hardly surprising that the ghettoes of Metropolis are far from Bruce's first concern - no mansions to be robbed there, after all.