I think you have good reasons for moving back. A good positive attitude is a nice thing. Trying to be one of the first to bring back a neighborhood is an excellent thing. Also, from a cost-savings perspective, it sounds like you'll be better off.

HOWEVER, you did ask an opinion-based question. Acknowledging your motives behind the move, there will still be lots of people that will say you are crazy. Personally, I would not make the same choice of neighborhood, but I wouldn't call you crazy. I call it idealistic. I'm at a point where I don't want to hope a place becomes nicer, but I want someplace already nice. I commend you for making a difference, and hopefully others will follow you.