They may not be students. I was quite disturbed when attending my niece's college graduation last month to hear her say she had $30k in loans and my sister had taken out $180k. My sister is 41 and hasn't worked in 15 years. Her husband is a decently well-paid glazier, but they're probably going to be in debt for the rest of their lives.
My stepdad held a lot of student loan debt until he passed away and it was all forgiven. He even thought of getting a PHD with another loan. I think that's pretty much the mentality/strategy of a lot of senior people.
At this point, that's basically my mentality too. Not to get a PhD, but rather that if I die before paying all my loans back, then I finally have the last laugh on the "higher education" system.