Several years ago there was a glut of diesel mechanic program graduates with poor job opportunities and a ton of debt from their for-profit schools. My impression was it was a similar situation for auto mechanics. Not sure what the current state of affairs is, but 20 years or so ago it sounded like a bad situation.
I'm guessing like a lot of things choosing a trade should take into account a person's attributes and interests, with some trades a better match for an individual than others.
For example, I'm not sure a person allergic to numbers with no attention to detail would be a good match for the machinist trade. Lots of things that might not be as obvious as someone with a fear of heights not being a good match for a job replacing light bulbs on top of towers.
