I think you're making distinctions that artists themselves don't make, and underestimating how much they can be financially motivated. The most surprising example I know is illustrated by this apocryphal story:
"...someone visited [Picasso's] studio, stood in front of a painting for several minutes, and asked Picasso, 'What does it represent?' Picasso replied without hesitation, 'Two hundred thousand dollars.'"
"...someone visited [Picasso's] studio, stood in front of a painting for several minutes, and asked Picasso, 'What does it represent?' Picasso replied without hesitation, 'Two hundred thousand dollars.'"