We already know that Bruce through the Wayne Foundation has already funded numerous social and economic programs. His fingerprints are all over Gotham City for his philanthropist (did I spell that right?) efforts but I do understand where you're coming from Chris. That would make for an interesting story pitch.
On the other hand, I can see where the incentive for being Batman comes from. Social programs and infrastructure investments like that are important for reducing crime rates in the long term, but that's statistics. There are still going to be individual people victimized by crimes, and so crime needs to be addressed on the particulate level as well as the holistic level. Being Batman is about trying to save individual people from having to suffer what young Bruce Wayne went through.
So one could say that Batman and the Wayne Foundation are a two-pronged crimefighting strategy, taking on both the individual crimes as they happen and the larger factors that lead to crime. Which seems reasonable to me, as long as the balance is maintained.
Sure, in theory, a better strategy for dealing with individual street-level crime would be to underwrite efforts to put more cops on the streets and provide them with better equipment and resources. But one thing that's generally been part of the modern portrayal of Batman (at least in the comics and the Nolan films) is that the Gotham police were extremely corrupt when Bruce was beginning his crimefighting career -- that they couldn't be the solution (and indeed were part of the problem), so someone else had to be.
So no, Batman isn't insane, and it's missing the whole point of the character to assume he is. His motivation, while somewhat obsessive, is a reasonable and beneficial one: he wants to spare innocent people from pain. He operates in a context where vigilantism is a reasoned solution to the problem of individual suffering, since no other solutions are feasible. And, as I heard someone point out when this came up at New York Comic-Con recently (sorry, I forget who it was), Bruce Wayne lives in a universe where costumed superheroes are an established reality, something that's proven viable and caught on as a trend. In our reality, a guy dressing up in tights and a bat cowl and going out to fight crime would probably be crazy, but in the DC Universe, costumed crimefighting is a more normative practice, an established part of the culture.
In short, it's not Bruce Wayne that's crazy and eccentric, it's the environment he inhabits. His behavior is a reasoned, calculated response to that environment.