Then came the 1971 Supreme Court decision in Griggs vs Duke Power Co. Now, any test which created "disparate impact" (ie, which had more whites passing it than blacks) was forbidden.
SO companies started figuring out how they could justify requiring college degrees as a way of assuring themselves, without testing, that the applicant had some basic literacy at least. The colleges, seeing an increase in demand, jacked up their prices. And so it goes