This is the principle of the "happy bottom quarter" — if you admit a class of 100% smart, studious, hardworking kids then the ones who end up at the bottom of the academic distribution on campus are going to be miserable and ruin the vibe.

But if you mix in a bunch of legacies, development cases, athletes, celebrities, etc who are pretty smart and happy to be there and don't have their self-esteem bound up in academics then the earnest grinds get to feel better about themselves and the networking is better too.

Senator-maxxing considerations militate in favor of an admissions boost to people from poor/rural states as well as for black/hispanic applicants, which of course is exactly what they do.