There seems to be a view that window washers, plumbers, cleaners, construction workers are somehow less intelligent than those who may be college educated. I don't think this labeling is in anyway kind or accurate.
You're correct.
I think it's a way people like to point out how the WTS holds people back when it comes to academic attainment. But as you point out, this does not equate with intelligence (or even knowledge). You could even argue that people who don't rack up huge debt for a worthless degree and the wisest ones of all.
They may even have the last laugh as AI takes over everything ... except for jobs like plumbing!