Earlier quoted context omitted.
This attitude is part of a more general cultural shift. Back in the 1960s, the majority of students said the primary motivation for going to college was to develop a philosophy of life, and a minority said the main goal was to be very financially successful. Somewhere around the 1980s this started to shift and the proportions are now inverted. * according to the UCLA CIRP freshman survey
Notably, the late 70’s and early 80’s is when large scale social changes started to happen due to high inflation and major problems in the US economy. Also a lot of social unrest, and a pretty unhinged president (Tricky Dick).
The stated rationale at the time was that degree holders earn more, so if everyone gets a degree, everyone will earn more. I am doubtful that was the true rationale but it's how the policy was sold to people.