The new movie actually addresses that by having his parents previously attempt to do "Gotham Renewal," but it collapses into a corrupt mob slush fund and doesn't actually help the disadvantaged at all. That's why he fights with his fists - because they will never collapse into greed like his parents' attempts at reform and reconstruction did.
Instead of tackling the systemic issues that cause the problems of gotham city (which he is directly responsible), he decides to beat people up. Kind of tells how shallow minded the writers are.
In the comics, the writers regularly show how he is directly involved with the Wayne foundation, which runs social service programs and provides aid for people who need it. More than once he has offered jobs at Waynetech to street thugs that are obviously just down on their luck and need a break.
This was brought up often in the 90s Animated Series as well as the Arkham games... unfortunately the movies rarely make time to show this. The Nolan movies tried, but it didn't come across very well.
The systemic issues in Gotham are regularly shown to be in spite of the Wayne family, rather than because of them. It's unrealistic, but hey, it's fiction