I'm not sure the problem is as bad as some suggest.
Firstly, loans are created out of thin air when they are made. That is how banking works. Prior to the loan, the money did not exist. After the loan, the money does exist. The true collateral for such loans is the borrower's risk of repayment.
If the loan is guaranteed in some way, that risk is zero. So the bank has no reason not to make the loan. (Failure to repay screws with the amount of cash a bank needs to keep on hand versus it's loan portfolio ... it varies because the Central Bank (in the US, the Federal Reserve) can raise or lower the requirement based on how they want to control the money supply .... but 10% is pretty close most of the time. So if they have $100 million in deposits, they can loan an additional $900 million created out of thin air by depositing the loan amount into an account or cutting a check. If someone defaults on a loan, they need to call in other loans to balance the cash reserve requirement. This shrinks the money supply.
That is all a long way to say that by getting students to take out a student loan, with no collateral and no payment history, you've taken down the psychological barrier that people who have never taken out a loan must get over. Once you've made one loan, you are far more likely to consider borrowing as a solution to a financial problem. This encouragement of borrowing creates money (out of thin air, remember) in the economy, which grows as a result.
The old rule of thumb was that every dollar created via an increase in the Money Supply will be spent seven times in one year, creating $7 in economic benefit. I suspect with electronic transactions and internet shopping that may be even higher today; the $7 figure comes from when cash was king (1970's) and you had to physically go somewhere to spend it.
All considered, Student Loans are more likely to increase prosperity as reduce it, especially since now we have a group of citizens who will borrow at a younger age and may borrow more in future than a similar young person without Student Loan experience. As borrowing is the major element in the Money Supply, this increases GDP and most other economic metrics versus a similar economy with less borrowing.
There are dangers of course ... inflation, and bubbles that precede crashes. Remember the part about calling in loans when someone defaults ... it shrinks the money supply and tends to cascade through the economy as businesses retract to cope. A bank that is having difficulty reconciling it's loans, defaulted loans and it's cash requirement, will not make new loans as it is literally against the law to do so under those conditions ... the ratios don't allow it until it becomes solvent with it's loan and deposit numbers which are reported and reconciled with the Central Bank every night.
But even with economic collapses (eg the 2009 fiasco) economies recover to the previous high quicker and economic metrics improve faster when the money supply was greater prior to the collapse.