Good points, actually, but can you clarify on what you mean with the government being the only buyer of student loans? All those other needs are permanent, too. "Roads" will permanently be under constructions somewhere, just as "loans" will always be outstanding somewhere. Fuel will always be needed, just in different grades, locations, and quantities.

Just to be clear on my point, it's not very hard to go and buy a portfolio of student loans for yourself (assuming you'd want them...)