If you rank order people and let in the top N, then increasing rank on the basis of any factor--race, for instance--necessarily bumps other people down. So for each person brought above the threshold, one drops off.

This is true regardless of how "all the factors as a whole" are used. Competition for a limited number of slots is zero-sum.

It might not be zero-sum for society; indeed, the bet is that the admissions criteria are designed to let in the people who get the most out of (and contribute the most to) the university. But in terms of competing students, it is necessarily zero-sum: the people who don't make it in are not aided by the people who do.