Only an educated man with a high wage job would come up with this crap. It fit the old template of, "Only suckers do what's expected. I'm too smart for that. Here's my plan that conveniently ignores all practicalities."
Putting aside the gatekeeping that prevents non-college educated people into high wage jobs. Putting aside the unskilled jobs have seen real earnings decline over the past decades. Putting aside that skilled non-college jobs actually require post-high-school education. One huge reason why people who don't go to college don't do this is... (Wait for it...) They don't have the money to invest.
The reason why people graduate from college with a load of debt, is because they didn't have the money to pay for college. If they had the money to pay for college, they wouldn't have the debt. This is obvious.
So where are these people going to get the money to invest? A bank? No one is going to entrust money to a high school grad to invest. For gatekeeping reasons, if no other. Second, why would a bank make such a loan, since they have their own investment arm? This makes no sense, and has no public benefit.
We know this doesn't work, because you can simply ask your older fry cook at McDonald's if they're raking in the dough with their investments.