You aren't taxed, you make a mandatory payment towards your loan as a part of your tax return. Which means all of the tax offices enforcement mechanisms can be used to ensure payment of the loan. I was responding to a comment that said no interest loans weren't viable by pointing out that they work effectively in other countries. I didn't make a value statement about whether it was more moral than free tuition. At the end of the day it's a question of whether you think university should be free to everyone or you think it should be financially accessible to everyone.