Why are so many borrowing money to get a college degree in a field which won't pay off? For that matter, why are we paying for so many to get high school degrees which don't pay off? The driver of a semi truck, or the cashier at a fast food restaurant, doesn't need to spend four years reading Catcher in the Rye and studying algebra.
That's not saying anything bad about those people or those jobs: they are no doubt good people and those jobs are important and valuable. What I am saying is that rather than automatically paying for everyone's college, we might instead ask what the point of education is, and whether everyone needs to spend four more years at school.
As you might guess, I think the answer is 'no,' and I think that the way that high school changed from something optional for a few to something required of all is instructive.
A better result, I think, would be to make government assistance equally applicable to vocational school, and to outright not offer government assistance (loans or scholarships) for certain degrees in fields with low employment prospects.