There is no "cancelling" debt. There's only forcing other people to pay.
The incentives here are entirely backwards. All the people who made good decisions around cost-benefit of their education, all the people who made frugal choices, all the people who worked hard for the delayed gratification of their long-term planning get penalized and have to pick up the tab for the people who spent 4 years partying without any concern about cost of their education or lifestyle.
This is just so evil, it's insane that people have been tricked by the terminology making it sound it's a morally good choice. Imagine if we instead cancelled car loans or mortgages- everybody who's driving a honda or renting an apartment now (through taxes) shares the burden of paying off the Ferrarri's and mansions, but they're still driving their junker while the people who had chosen to load themselves with debt get to enjoy their sports cars and houses.