The problem lately is that the time and investment needed to get into a lot of different high-paying fields, is that the technology changes rapidly, AND that companies would rather engage in wage arbitrage rather than update existing employee's skills.
The upshot is twofold:
You can pay big $$ (if a US citizen; many foreign students get sponsored by their home countries) for a degree which might not pay at all (your specialization went out of favor while you were in school; by the time it is hot again, your learning is out of date), or you can hit at the hot time and have five, eight, or ten years, before which you need to start over in the next hot thing, or get outsourced.
And when you enter the new field, you have to compete against others even to get the trainging; you have to earn a living and may have a family to support, so you usually can't do full-time day studies; and when you get out you are competing both against lower-wage foreigners and against people just out of school who are younger *and* cheaper than you; and your prior training and experience is often seen as a liability, not an asset.
In the short term, good for the bottom line of the execs of the businesses, bad for most everyone else in this country.
Cheers!
Unfortunately, you are absolutely correct.