I chose my above words carefully: It was an issue of SATs, not qualifications in general.

Prior to affirmative action, SATs were the be-all-and-end-all of equilibration for GPAs; A GPA of 3.9 at the Bronx school of science was not the same as 3.9 at Rural High. Along came some studies showing that the SATs (esp English) had some cultural biases.

The admissions depts were truly trying to figure out: Which candidates will have the biggest impact after graduation? SATs were called into question as a predictor of that, and that "standardized" tests were maybe not so standard after all.