One can argue that those who pay off a $250k college loan to a small liberal arts college are creating a moral hazard for loan issuers and college adminstrators who keep jacking up tutition.
The article proposes that if everyone were to default, educational costs would be returned to a more rational level.
Personally, I think that the cost of college education will continue to increase to a significant fraction of the value of the college education, to somewhere around half a million dollars. This is basic economic theory, and will result in fewer students finishing college, and a continuing increase in crushing debt.