That's the whole point.
Plenty of people not going to pay it back because they have their aspiarations unfairly raised. So who foots the bill? The tax payer!
Fewer unis and places means less to spend initially. There are only so many positions available each year that genuinely require a degree. Once these are taken by people of the cailbre needed, they start to pay back by means of higher taxation.
As it is too many people with nondescript qualifications will not earn the higher salaries, and will therefore not pay back the money.
In some instances employers are having to introduce their own tests to differentiate between prospective candidates.
I worked for quite a while at UMIST, and the average quality of student changed markedly in that time, as it became a game of numbers, bums on seats bringing in the dosh. Upshot was the lesser able folks who in all reality shouldn't have been there made it more difficult for the better ones.