They will not move their families into a predominantly Black neighborhood, because they know that Black folks are more prone towards criminal behavior. They know that if they move their families into those areas, that their wives and daughters will be raped, their sons will be beaten or killed and their property will be stolen or destroyed. They know this. They understand it completely. Their actions prove that they understand, because not only do they perform the passive act of not moving into Black neighborhoods, they take the active step of moving their families away from neighborhoods where Blacks have started to move in.
White folks know that diversity is dangerous.
If diversity were truly wholesome and wonderful, if diversity were truly worthy of celebration, White folks would be celebrating it spontaneously. They would look at history and cite all the wonderful examples of the great nations of earth that had celebrated diversity and thereby reached the very pinnacle of civilization. They could point to all the happy people who lived in strong, healthy, and diverse nations throughout history. The only problem with that scenario is that there are no such great nations, anywhere in history. In every case where a great nation turned to embrace diversity, it went into a fatal fall never to rise again.