>> it merely means that 
  >> studying the respective field is less likely 
  >> to be very economically rewarding

Um, no, I'm gonna have to disagree with you on that one. Paying hundreds of thousands of dollars in borrowed money for something which doesn't provide any ROI is IMO bullshit, particularly so if you can't discharge the debt under bankruptcy.

Your examples are bad too, because back in the day all those painters, writers, etc, were either independently wealthy already, or did other jobs before they became famous. H.P. Lovecraft, for instance, worked as a traveling salesman. Van Gogh both comes from a wealthy family _and_ had a job at an art dealer. And there are very few of such people anyway, it's not a viable route for most people, it's more like a lottery.