This take is short sited at best.
How can you force someone to go to trade school? What you going to do if they don’t show up??? Throw them in jail?
What happens when I have multiple baby mamas? Do I have to pick up a second trade?
Certainly you can't force anyone to do anything. But you can incentivize them.
If there's an option for free trade school or discounted loans or deferment, people want to do something, they just don't always have options to do so and those options become more limited once you are already in a hole. If you rack up 10gs in credit card debt you can't just join the military and have your credit deferred. Obviously options become limited if you go to jail and can't get federal loans and shyt.
People have this belief that because some people ain't shyt they just never wanted to do anything or that they just don't want to. People need opportunities and more isn't a bad thing.
Keep in mind this is just a basic proposal not ever detail, exception and policy has been addressed or fleshed out for implementation. Everything you can think of has those same questions. Farm bills, scholarships, loans, housing bills, etc. And they've been implemented for decades.
If you don't qualify or don't meet the need it's foolish to ask "well, what about me?"