I don't think it's a simple as MSE makes out

* debt incurs interest at rates way above what someone could get a personal loan for

* it still affects people's ability to borrow when it comes to house buying etc

* if your parents are rich enough to pay your fees then you don't pay the tax

* if you earn enough to pay of the debt quickly they you'll pay less than someone with a middling income who earns enough to pay a lot but not clear the debt

Just make a proper graduate tax instead is my view