I didn't think I needed to be so specific that the curricula needed to be specified when I referred to the salaries and I would think you know that I meant the studies in areas where there's just about zero demand for people with that experience.
STEM always has demand and those fields are objective, which means there's a need for accuracy, completeness in the material taught and hopefully, they impart some sense of the real world WRT what they can do in it.
Parents have taken the easy way when it comes to dumping their kids at school and picking them up (maybe) at the end of the day, without being involved in their education and I think that part of the reason they aren't very involved is that they may not have been particularly interested in some of the classes that are being taught when they were in school. Imagine being a parent when they realize they can't help the kid(s) with their Math homework because the kids are at a more advanced level- some kids are doing algebra in 4th grade (I don't know when they officially start that level but we only got to pre-algebra in 7th or 8th grade).
WRT your comments about people who don't need to go to college- absolutely! Some kids just aren't going to do well there and would rather do something as soon as high school is done- I know of many who entered the trades while we were still there, participating in co-op programs. Some tried college and decided it wasn't where they should be and some went for a while before reaching the impass of not knowing where they wanted to go. The high school I attended had strong shop programs but not long after I graduated, they lost the entire staff after forcing the drafting teacher into early retirement and with the trend of parents deciding that "My kid is not going to work with their hands", the programs were doomed and that, coupled with the loss of so many manufacturing jobs, set up the country for the future shortage of skilled workers. Also, as people became more affluent at younger age, they saw less need for doing things for themselves, which was taught to the kids, so the next generations didn't know which end of a screwdriver to pound on.