1. White people commit racism and violence against blacks
causes
2. White people flee to the suburbs
causes
3. Urban centers to deteriorate.
Let's examine:
1->2 So white people were fleeing... their own violence against blacks?
2->3 So when those violent people left, this cause the areas to get... worse?
Apparently you believe white people being present is a problem, and white people leaving is a problem. Their presence hurts blacks, and when they leave it hurts blacks too. So literally everything is the fault of white people, whether they're coming or going, here or there.
Even more surreal - these blacks voluntarily moved towards the whites. Then the whites moved to escape the blacks. And the bad guys here are... the whites! The ones who blacks want to live around, and who are trying to flee them.
It really is remarkable the rationalizations a mind is capable of.