This is the wrong question to ask. The question should be, "why is this behavior EXPECTED and tolerated in these areas?" Regardless of how poor an area is, why is it that these shitheads have absolutely no fear of robbing a family in broad daylight, and no moral compass around putting young children in harm's way?
It amazes me that the people who live in the neighborhood could put an end to this **** with some well-placed bullets or cooperating with police, but they refuse to do it. Then wonder why their lives are so ******.