3. Dwindling population, in general, or just of graduates, will destroy the system.
This was the first thing I thought. It would be exactly like social security. It works when the population is stable or increases but breaks down the population decreases. Actually, it would be even worse than social security seeing how the more educated tend to have less kids.
Another problem that is shared with the current easy student loan access is that universities would probably try to overcharge since they known the people using their services are not going to discriminate on price.
Physician: One upon whom we set our hopes when ill and our dogs when well. -- Ambrose Bierce