Not that I agree with the original, but that's a bit like asking why would anybody play music or make art (activities that rarely involve money)? Because they enjoy it.
There is the argument that what the market wants is not always the "best" or "most innovative", but the value of art is basically determined by a "market" (even if the artist seeks validation rather than $$). It's a subjective matter, so such a problem is somewhat inherent.