Busting your ass as a plumber with the goal of eventually being the guy that owns the business (or whatever) can be the pragmatic choice.
Licensed trades have gatekeepers, e.g., my high-school friend couldn't be an electrician because he couldn't get a union internship. They were full and he didn't know anyone important. Also, I believe that the licensing required the completion of course work.
I have never had a job that didn't require college and also paid more than rent. It seems a strong assumption that there are ready alternatives which pay a subsistence or higher wage. Of course it is also a strong assumption that higher education will necessarily result in a subsistance or higher wage, but my point is that it seems unfounded to simply assume that there is a reliable practicable alternative just because there used to be. As far as I know, I don't know anyone who didn't go to college and can reliably pay rent by themselves, and I know lots of people who didn't go to college.