Exactly--- Art is for yourself, something you almost have to do. Money isn't the reason (though it is nice).
That is why I don't like the NEA, it makes art something that it isn't.
If the artist stays genuinely clear of noting the price/which works have sold, he will continue to create what he wants rather than trying to squeeze out more "money makers".
Van Gogh painted works for his brother to sell. It didn't happen much (his brother died 6 months later I believe so Vincent's nephew inherited the works and kept them).
Vincent painted a lot of self-portraits and flower pot paintings. He did some knockoffs (interpretations) of Japanese prints.
There is only one famous painting of his room, only one Starry Night.
There is something to be found in the paintings he did variations on but there is a spark in the unique/singular works.
Photography allows me to "give" a customer "one that looks like that" without having to keep repeating myself. They want one like that, they get "that" and yet there is still an original creation in making the print. Art prints can be beautiful too but the complexity to make a print (especially from a painting or drawing) pulls the artist out of the control of his own work.