Getting a degree simply to get a degree is one of the failings of our higher educational system and the high cost of tuition doesn't usually justify those degrees.
The perverse disincentive of doubling tuition for degrees with expected low workforce value might reduce the number of undergraduates who have such deemed unnecessary degrees in the workplace, but what then do you do with those post-secondary school students who feel that a college degree is useful, regardless of what that degree is in?
I think we need a renewal of trade schools, apprenticeship programs, and a movement to more practical degrees.
Of course if you truly want to study advanced art or literature or history or theater, there should be a path for that, but the future for those in those fields are not in high paying jobs, which means that the tuition will very rarely be returned to the student in the form of wages.