In principle, I agree: when I see kids take out tens or hundreds of thousands in loans, and not get a productive career out of it (say the guy who couldn't pass the bar after going to law school), I don't have sympathy when they claim they shouldn't have to pay the loans back.
In this situation, however, I believe those not paying are claiming they were deceived (and there are lawsuits as such). This isn't a matter of not paying your loans because your house burned down, as much as not paying your loans because the builder deceived you on the quality.
Additionally, these aren't typical bank loans usually, but guaranteed by a quasi-government entity. To a certain degree, this means the government is guaranteeing some set of standards (I can't get a government-backed loan to do a code bootcamp, for example), and these students are banking on the idea that the loans will be forgiven without recourse, or at the very least, shining a light on this school with they are contacted, en masse, for failure to repay.