You mostly get a few groups complaining about the burden. People who don't know about income based repayment, people who make too much to qualify (basically what they'd pay if they paid 10% of their discretionary income is higher than the standard 10 year repayment plan), and people who took out private loans to go to for profit universities, or expensive private schools that weren't top tier (private loans are only 7% of total disbursements).

Add to that the arm chair analysts who see news stories about student loan debt and complain for them.

That's not to say that some of these grievances aren't legitimate. There really are people with $100k loans with useless degrees from for profit universities, but they are a small subset of loan borrowers.