It has to go deeper than just entrance exams. If they are too stupid to take the entrance exam then they are probably too stupid to pass their classes. Is someone going to class for them, taking their exams, while they are out partying? Who is covering for them?
I wonder if something similar is going on with Harvard's HUMA (Harvard Univ. Muslim Assoc.) Student gets in, gets a degree, goes anywhere in the US because of said degree.