Really? Why do you think that? I know plenty of teenagers who got jobs outside of retail or food service, did meaningful work, and got paid decently for it. I think if given a challenge, most teens would do surprisingly good work -- the problem is that we expect teenagers to be useless, so they behave accordingly.
In my case, I did a high school apprenticeship at NASA (and they did actually call it that a few years ago). No real lab experience outside of a basic chemistry class. Same thing for my 14 peers in the program.
