Also because liberals don't want to uplift or help blacks or any other group.
Liberalism is not about helping people, it's about making a statement about one's self.
A liberal cannot stand to see a black who is truly educated, intelligent and articulate because that means that the liberal can make no statement aobut himself.
When a black is uneducated, stupid and inarticulate, the liberal can hire him or her and make them managers of companies in order to make the statement "Look how generous I am."
A blakc who actually deserves to go to an ivy league college or get a high paying job is worthless tothe liberal and therefore the liberal will sic the dogs on him ie. the millions of uneducated, stupid and inarticulate blacks who are more than eager to demonize any decent black person by refering to him as an uncle tom.