I am afraid you don't know what you're talking about. Most of the loans on Sallie's books are Govt guaranteed. Second, about 90% of the loans that are not guaranteed have co-signers..like a parent...so two people have to default. Neither of these loans cannot be discharged in bankruptcy (if they could interest rates will rise to credit card levels). If people all of a sudden stop going to college or stop borrowing to go to college (both nearly impossible), Sallie can survive on existing assets for a while..
90% are not cosigned...The Smart Options loans are close to 90% co-signed. Private student loans and Federal student loans can be discharged via bankruptcy. Need to file a petition and complete means testing.