You left out the part about student loans have special interest rates and delayed payment schedules and they were subsidized by the federal government.
I should also write that in the US, education is constitutionally the realm of the states. There is no constitutional duties for education at the federal level. All states have state university systems, with large campuses and land often set aside by the state constitutions, along with subsidies at the state level. Having student loans at the federal level should be unconstitutional in the first place, but in practice also gives a green light for states to get as much federal money flowing into their states as they can, using the students as intermediaries.