Not all students go on to become particularly privileged. Many fields require educated employees yet can't pay for those.

Also, in many places the state himself requires some level of university education for some positions. Essentially instituting a cost of access for government employees is a scary proposal.

Finally, price discrimination means shutting up the universities to the poor ; making the university education premium yet higher, and going yet more disproportionately to those already well off. Since the state is anyway going to subsidize university, that would mean an even more regressive subsidy.

Un roi sans divertissement est un homme plein de misères