In an earlier post, you made it sound as if teachers were the ones promoting this idea - the "education system and society have made people think certain jobs are below them." A quality teacher has interest in seeing their students be highly successful at almost any occupation (I couch this with the fact that a quality teacher will not support demeaning, damaging, or illegal occupations like Crack Whore). One of my friends from high school is an elementary school maintenance worker/janitor; his school had an appreciation party for him and the principal talked with the students about how the school would have difficulty functioning without his services. But, I digress.
To understand where mindsets come from, look up the food chain. The most cockamamie and crazy ideas tend to come from state departments of education, where administrators have lots of book smarts but usually precious little classroom experience. They think their ideas are great, then toss them down the chain and are surprised when they don't work out (and it's obviously because of those crappy teachers). Tennessee at least has the sense to keep vocational secondary education viable. I would argue they're not pushing it hard enough and making it more widely available.