That assumes jobs are available.
The current regulatory/tax/tort environment makes it risky to employ young, inexperienced workers. It often just isn't worth it.
Student loans have been masking this problem for years. The employment rate for 18-24 year olds is just 54%. Nearly 40% of that age group are in college. WIthout loans, the unemployment rate would make a nice jump -- and the government doesn't want that. It might make them look bad.
So what are you arguing—that we should continue to dish out humongous student loans to marginal students like crazy AND not make them pay them off?
If you’re a college grad, which is when you’ve got to start paying back your loans, you sure ought to be able to get a job at something. Many of those hanging at home are just waiting for their dream jobs, or choosing to take unpaid internships on the hope of advancing into a dream job. They really are about the last demographic taxpayers should be subsidizing.