Perhaps I picked a bad example, but for most of his art he was, in fact, paid for it. And it is hard for me to imagine that he would have had the resources to create, say, the Sistine Chapel ceiling if he were doing it for free.
Of course, nowadays our idea of art is a mashup, so maybe that can mix fine with an anti-market ideology.
Of course, nowadays our idea of art is a mashup, so maybe that can mix fine with an anti-market ideology.