I am open to persuasion, but I think I'm of the opinion that a private school can exercise discriminatory admission practices based on whatever factors it chooses. I think the same principle applies, long-term: discriminate based on factors that are counter-productive, and the quality of your graduates (and therefore, the prestige of your university - at least, for schools that still value their graduating students over their professors' research) suffers.
No need to persuade, we're of a like mind.