If you want a career as a pilot... 4 years of college won't offer any benefit over a technical school devoted to aviation training. But good luck getting a decent job with out a 4 year degree.
What do you mean by a "decent job"? In my experience, the only time you would probably need a degree is if you're aiming for management or executive-level employment.
Depending on your field, you don't even need college. For instance, I started off reading computer certification books, took a couple of exams, and went from making $11/hr to $17/hr within a year's time, granted, I needed to leave my first job.
A little hard work and willingness to learn, and you can get a pretty decent job with livable wages without too much of a problem.
And I used to agree with you on your other point... that is getting some specialized skills without a degree. Plumbing for instance. Too many people felt crawling around a leaking poop pipe was beneath them... but a great living could be made. However now you cannot survive against these companies that hire illegal labor. They hire a number of illegals to do the dirty stuff with a skilled plumber overseeing the work. That company then could get a lot more done and charge less on volume. For a young plumber starting out it will be tough.
Really, so what about the illegal labor part? You cannot worry about that. The point is you'd have a marketable skill that few have and most people probably aren't willing to crawl under a nasty toilet or sink to fix something.