If you don't find a good job and end up working in fast food, do they still take 17% of your salary?
You get an interest-free loan for your education, the only thing it accrues is inflation. The loan is repaid as a percentage of your taxable income if and only if that taxable income is greater than 54k or so. It means that you will potentially never be asked to repay your student loans if you never find professional work.
Federal loans (90% of student loans) are paid directly by the government, and come with income based repayment plans capped at 10% of disposable income.
The debt is cancelled after 20 years, so if you don't find a decent job, you'll pay very little.
There is interest though.