Except those black communities are usually doing it in retribution towards the racist policies of whites. It's a vicious cycle. The ones most likely to be bigoted towards others (the young and poor) are the ones who get pulled over, followed in stores, have people cross to the other side of the street, etc. However, these people have much less influence in society than say police officers (not saying that all officers are racist of course), judges, employers, etc. That's where true systemic racism exists, and that's where it hurts the most.
Also, on an earlier point you made about colleges, I think that it's perfectly acceptable to look at an applicant's race during the selection process. The whole point of a university is to foster a broad range of debate and intellectual discussion with people of different backgrounds. Don't forget that colleges also weight the applications of religious minorities and rural students for the very same goal.