Bravo. You understand that textbook economics (and a huge chunk of research economics) is a hilariously oversimplified model of the fiendishly complex field of human interactions.
I believe it is simply useful for many people to be able to state textbook economic orthodoxy as "a fact", even if it is almost trivially broken (as the supply and demand curve story is on many levels) or historically wrong (as the fable of money arising from barter). This lets people justify all weaknesses of the current economic system by simply saying "It may suck, but this is what it is, a law of nature. We can change it about as well as we can reverse gravity. Conform, and propose no change."
I believe it is simply useful for many people to be able to state textbook economic orthodoxy as "a fact", even if it is almost trivially broken (as the supply and demand curve story is on many levels) or historically wrong (as the fable of money arising from barter). This lets people justify all weaknesses of the current economic system by simply saying "It may suck, but this is what it is, a law of nature. We can change it about as well as we can reverse gravity. Conform, and propose no change."
Might be me which is just cynic though.