Which makes a lot of sense since income correlates with intelligence and intelligence is partially heritable.
A century ago the SAT was used to fine diamonds in the rough for first-generation college students. After multiple generations of college students mating with college students, you're not going to find that many first-generation college students anymore.
Inserting dumber students into college because of their upbringing is hostile towards the success of a nation.
EDIT: Please point out something that's incorrect instead of downvoting because it makes you uncomfortable.