I have always seen Ivy League admission controversies as stemming from the fact that the number of "perfect" (as measured by objective criteria) candidates is so high versus available spots, that there are only two solutions:
* Select candidates randomly from a pool of perfect candidates.
* Select candidates based on additional, subjective criteria.
The first approach seems inherently fairer, but schools went with the second approach. It's hardly surprising that all sorts of biases creep in.
I once read that a candidate was rejected because, having an enormous amount of extracurricular activities in his CV, was deemed "too intense".