It's not unambiguous because it doesn't take into consideration other factors. SAT scores are the only variable mentioned in your article, but they're not the only variable in whether a college accepts a student. They've become a less and less important factor over time.

At some colleges, a low SAT score would prevent you from being admitted by a high SAT score wouldn't increase your chance of getting in. Colleges value GPA, class ranking, letters of recommendation, sports participation, extra-curricular activities, personal essay etc etc. It is possible that Asians have done worse on those other areas and aren't getting screwed by quotas or affirmative action.

"Used against", to me, implies active planning that may or may not exist here;

Ahh, the old 'malicious or incompetent' dichotomy.