I have two views on this.
If someone, of any age, has been stupid enough to secure their flight training debt against their families homes then the risk is all theirs. Bankruptcy is not and should not be an option. It can not be. These chancers will get what they deserve ultimately. I know that I certainly wouldn't have put my parents home up as security for flight training so that is my justification.
If someone is offered unsecured debt to carry out flight training, the risk is all the banks, they have employed highly paid risk analysts and number crunchers to weigh up the risk. If you want to be a pilot, you'd be a fool not to take it given the chance. If you can't pay it off or it is strangling your life then the sensible thing to do is relieve yourself of it. That risk has been bulit in to the loan. Taking into account the fact that WWW very correctly pointed out that the money never actually existed, just makes the whole process feel that little bit better, fair and even.
In the second, unsecured case it is perhaps exploitation of someones 'weakness' but then again so is what the likes of Ryanair do and people seem more than happy with that don't they?
Everyone needs to do what they need to do and 18-25 year olds that have tapped their parents up with a huge relatively short term debt are going to need to grow up and wise up pretty quickly.