There are several of these people/stories out there. All still use some kind of currency, though. Usually favors, or they trade physical things. What's wrong wi

There are several of these people/stories out there. All still use some kind of currency, though. Usually favors, or they trade physical things. What's wrong with a paycheck when you're doing work that solves a problem? It's still a system of mutually-beneficial trade, yet it's seen as less noble. Why is that?