A basic assumption about debt is that it will be paid back with interest at some predictable time in the future. Debt increases the money supply without an immediate corresponding increase in total good and services. It is only because it is repaid that debt does not debase the currency. Canceling a debt without permission from the investors is no better than stealing it outright.
According to this petition 86% of the $1.3 trillion of student debt is owed to the United States government. The petition encourages that government to forgive all the debt. Not just the public part -- which is bad enough -- but also the 14% that is not public. No mention of consulting the taxpayers who finance it. No mention of how much more the taxpayers will have to cough up to make the lenders right. Just eliminate any possiblity of the debt ever being recovered.
It is no surprise to me that the list of sponsors include the American Federation of Teachers and the Daily Kos. Both of those groups seem to believe that feeding their sick, elitist egos somehow justifies stealing from the middle class. First by wasting our taxes then by inflating the currency so our incomes are worth less.
The cycle of inflation and debasement has ruined civilizations in the past. The rules for that haven't changed; only the names of the criminals varies.