Yes, it would, it does, they should and they often do. When they don't it tends to be because they're struggling to have their other needs fulfilled.
I think plenty of artists would give away their work for free without second thoughts if they didn't have to make it pay their bills.
Yes, I understand most artists would be glad if their landlords accepted "exposure" as rent.
Similarly most salespeople would gladly work commission-free if it meant more sales.