Poor Drafting Practices
I agree, I spent 4 years as an apprentice before I could call myself a detail draughtsman, then a year before I became a design draughtsman. I was taught originally on the board although CAD came in quickly when I'd finished my training.
I've come across some very poor draughting standards in my time but one of the worst and most common things I've found is "drafters" not knowing how to lay out a drawing........first you draw a plan I tell folk, it's not called a plan for nothing you know. I guy I worked with once produced a drawing of a weldment with a view on the underside, perfectly acceptable if he'd annotated it "view on underside" but no, he'd drawn it at the top of the page and therefore everyone thought it was a plan, caused a lot of confusion and almost a day's loss in the workshop..........
Draughting standards are slipping for sure, there's no or little training anymore, the best you can expect is the trade school courses you described, it's the industries fault, no investment in the future because CAD can do it all you know.