Point 1: I agree that flight training is a very expensive risk but tube drivers don't fly hundreds of passengers 36,000 feet above the ground going 500mph.
Point 2: If you're fortunate enough to have gone through FTOs such as CTC, OAA or FTEJerez then you're in a good position to get an airline job and pay back your loan due to their airline connections. A family friend of mine graduated from CTC in 2010, got a job with easyjet that year, bought a pretty big house and a brand new audi tt while his loan was payed out of his wages every month (almost £1200) and barely noticed it. My point (which may it may not go down well): Don't believe that every pilot graduates and is jobless for years and in debt and never lands an airline job, you just have to have the drive to go out and get it! Believe in yourself and work hard.
All that being said, I may take all that back when I graduate from CTC and don't have a job lol, touch wood.
Ps. I recognise that there are unfortunately pilots that have been landed with a huge bill for their flight training and have been waitin for years for their first airline job and hope that they find one soon.