Apprenticeship programs start with a minimum wage and as the apprentice masters each level the wage goes up, this happens for the apprentice regardless if s/he is 17 years old or 50 years old.  If $15.00 an hour is the going wage for the apprenticeship level, the apprentice's age should not factor against her/him.
     
Also, every apprentice requires the supervision of a journeyman while learning, the journeyman "babysits" the apprentice regardless if the apprentice is 17 or 50.
     
Vocational arts programs helped many in my generation go into professions that allowed them to live well and save for retirement.  These are jobs that cannot be outsourced like many of the mill and manufacturing jobs have.  
     
Some students don't have the capabilities to tackle a university education but do have the capabilities to masterfully become a journeyman trades person.  If we are going to spend money on college prep courses, we need to also spend money on vocational arts courses, too.