It is a fact that a relatively small percentage of accepted blacks actually enroll. There are several reasons why relatively few accepted blacks enroll. The number of race-based points toward acceptance a person receives doesn't matter if a prospective student doesn't believe they'll feel comfortable on campus. I'm describing is the feeling that you don't belong. Classes were stopped so the students at that time could fight for slavery in the deep South.
People are creatures of habit and tradition.
In addition, when desegregation actually did occur, the motive was economic and not moral. That is, our school was integrated in order to receive federal dollars, not because it was the right thing to do. As I said, we as people are creatures of tradition. A person's values are taught from birth by their parents. When you give points on the admission scale for being a descendant of a person who attended the University, it's very possible the same closed mindedness that has existed throughout history is still alive and present at the University today.