This isn't a European style system where your living expenses are paid while you go to school. They're just getting their (already cheap and routinely subsidized) tuition paid.
It's already a stereotype for somewhat directionless kids to hit up CC while they work some deadend job. Maybe a few more will be tempted to do this now that it's automatically free, but it's a minor cost and can really benefit some of them.
The true fuckups aren't going to want to spend any more time in school, free or not. The dedicated but poor students are going to benefit. The idea that this incentivizes people to cynically slack their way through high school and CC and backdoor their way into an excellent university is nonsense, no one is going to do that (for many reasons).