This is much more of an issue when you use the methods outlined to argue against an idea. If instead you use these methods internally, this is less of an issue.
Universities are naturally xenophillic--both in their desire to understand more about the world and in their desire to influence it. Exploration and openness to new experiences and ideas are also important intellectual values important to develop in students. All of these are enhanced with a diverse student body.
As a more concrete example... $IVY_LEAGUE doesn't gain that much by having its average standard test score go from the 99th to the 99.5th percentile. From the university's perspective, it gains more by admitting students who spread the influence of the university's ideas, enrich and enlarge context in classroom discussions, etc...
Assuming accurate tests and a normal distribution of scores, shouldn't that be approximately equivalent to going from the 80th to 90th percentile?
For example, at one time progressives were trying to end segregation and promote judging someone on the content of character and not the color of their skin while conservatives fought them on this. Now progressives are trying to reinstitute segregation and promoting the idea that people should be judged on skin color and not content of character while conservatives fight them on these changes.
That's quite a statement. Could you go into more detail?