Bruce Wayne is a multi-billionaire. If he cared about crime in Gotham City he wouldn't have gone after Joker in the first place. Instead, he would use his batmobile money to fund the mental health programs that cut off Joker's medication and therapy.
Bruce Wayne could fund colleges, trade schools, drug treatment centers, and other programs proven to reduce crime. Maybe use his influence to negotiate higher pay for civil servants so they don't have to take bribes from criminal gangs.
Instead, he plays dress up and assaults Gotham's most desperate citizens. Batman is a perfect example of the billionaire class's ego and selfishness.