Purely my opinion, but making college at a public university free is only going to diminish (further) the value of a bachelor's degree, while further diminishing the actual value of trade schools, tech schools, etc. One area where I think Mike Rowe is dead on is that we as a society have failed to appreciate the value of people who do real work for a living. People who do jobs that are very necessary in our world. People who get dirty at work, who build things, fix things, clean things, and tear things down. Start pushing for everyone to go to college because it's free, and suddenly a whole lot of kids who would have gone to work in these areas, and may have done well at it, will go to college if for no other reason than it's free and a way to avoid growing up for another 4-5 years. And when people start treating college the way we used to treat high school, some place you're expected to be, how long until the quality of education goes down? Colleges aren't going to flunk kids out if they're getting .gov funding for each butt in a seat. So suddenly classes get easier in some fields, and a diploma suddenly becomes the higher education equivalent of a participation trophy.
Looks, there are lots of ways to pay for college without making it free. My father worked full time while getting a BA and M.Ed. His friend paid for school via GI Bill. There are tons of scholarships. There are co-op programs. It can be done.