Your comment sounds a lot like you have no idea what kind of hell it is to start a normal job after college, at least compared to running as a pro. Or that you know, but you were so slow that trying to be a pro was never an option.
It's about passion, and how you spend your life, at least until you cannot run any more. Running as a professional sounds much better than 8-5 office job, no matter how much you earn. And it's not like he will run as a pro after the age of 40. And his Harvard degree is not going away.
I'm passionate about my great job/career... Going to a great school allowed this luxury...
Don't kid yourself. "I ran for 10 years and I have not had a meaningfull job in the last 10 years doesn't cut it at an interview (even if you have a Harvard degree)"
I would understand trying to go pro, if he was "say" an Oregon grad however.... But Harvard?