*Groan*. What something is worth is dependant on demand, these are not seperate qualities. You could have the original holy grail sitting on your coffee table, it wouldn't be worth a penny if nobody in the world wanted it. I can't believe I'm having to explain this, it's downright trivial.
You're just being moronic: when hiring, managers very very often consider how much the person is worth - it's all still part of free market dynamics (mostly because the person who is worth more is more desirable for that job, and the person knows that and can bargain with it). So your assertion that "jobs don't pay what the person is worth" is stupid, and is evident in the fact that people with degrees doing the same job as people without earn more, likewise for the gap between people with a bachelor and people with honours/masters/Ph.D.
Now I expect you to try and bugger around with semantics (such as implying worth is an aspect of demand) and make us forget the fact that you matter-of-factly stated "jobs don't pay what a person is worth".
Am I implying McDonald's pays what a person is worth? No, because the McDonald's labour market is saturated. But jobs markets for professionals are another matter entirely.