I get the sense that they might feel stuck and without any other options in dealing with it once they realize they’re in over their head. Blame whatever you want - the fact that cars are so absurdly expensive now, the predatory lending practices, America’s car dependence, the dude only caring about the payments - people like this are just completely unequipped for any transaction with an entity like this other than watching their money disappear. If you were about to lose your only means of transport to your job and found something that sounded convincing to keep it, would you rather try it or for sure lose your car?
That said, suing Bank of Freaking America is the most boneheaded thing anyone in the US can do.