This story is as sad as it is common. Regrettably, I cannot suggest how to advise him. I do know one or two financial professionals who might have interesting perspectives. If so, I'll will post again.
I just wanted to add to your example. I knew between 20 and 50 men and women who studied law then did not practice, then realized the duties of their state in life. Also, I knew men who married professional women with college loans for medical school, then hired nannies and had them return to work. In one case, the woman promised to work free for four years to clear debt. They conceived, and she had to go back to work.
I don't think one could argue that they don't owe the money. Still, in my grandparent's day, financial difficulties were often resolved by living with extended family.