I'm not sure it's just that.
There are some built in issues that are problematic to being able to pay the money back.
The main issue is how do you pay back $100,000+ in student loans with the poverty wages ($20,000 per year) that the airlines pay their first officers once you finally get a job working for them?
The other (secret) issue is there is an 87% washout rate in the training portion of this industry. For every 100 students that start to train as a pilot only 13 of those students actually receive a private pilots license. So a student that does not complete his training, for one reason or another, can not possibly pay the loan back with earnings made from being a pilot.
Keep in mind that there are flight schools with business models that collect huge amounts upfront with the full intention of getting those students to quit or leave so that the school can charge a huge cancellation penalty or keep the unearned tution entirely. This also leaves the student on the hook for a large student loan that they can not possibly pay back.
At the very least, I would not consider student loans for anyone that does not already have their private pilot license.
Joe