Why should there be a purpose to art at all? In any case, Oscars are known for handing out awards to non-commercial movies. That was the entire point of the awards. To reward excellence, not money (modulo human factors).

If you are not going to be entertained by a movie, don't watch it. If you don't like the authors opinion, move on and go read something else. Maybe I should move on from your opinion too :)