> underpaid and overpaid?

there's two "meaning" to being underpaid; 1) the work being done is captured by another party, and thus underpaid to the worker doing the work. An extreme example is slavery - they are underpaid.

2) the second meaning of underpaid is the perception from other people that the profession is producing value for society, but the payer of that work (usually tax payers) is not compensating for the value dispersed throughout society. Examples might be teachers.

I can understand the first notion: the 'price' offered is not enough to clear the market. In your example, there are fewer people who voluntarily would be doing slave labour for slave wages, than willing employers.

The second is a bit nebulous. I think it's mostly down to social desirability bias: people say stuff that sounds good, but doesn't make much sense.