If wealth is a huge predictor of how well you score on a test or how many AP classes you can take that means these very standard ways of judging someone's admission to a college is not merit based, it's income based.

Wealthy children can pay more for tutors, have access to more resources for help and generally have better funded schools which help them perform better. Non-wealthy and many times minority children, do not have access to these things as often. Admissions processes are set up in a way that inherently gives an advantage to white people to go to college. Affirmative action is basically a more overt way of giving an advantage to non-white people.

So I ask you how are things that are so highly predictable by income 'merit'? You came into this conversation on the assumption that the current process without affirmative action is a meritocracy, when it reality it's not.