well i dont mind a film being art or entertainment, or a mixture of both, i will take it on its merits and judge it as it is.
i take your point, i think it was a bit beautiful without loads else, but this time there was a message about grief and allowing yourself to drift away into dreams and grief and so on, to repair or realise the way forwards (hence "you cant wake up if you dont fall asleep").
on your last point i disagree, you can be artistic alone if you want, it is completely up to the film-maker. You dont have to be at Sundance to produce a beautiful bit of art, look at the 100s of 'world' cinema films (i dont like that term) that are produced for arts sake. Granted they dont get far financially/commercially, but it is enough on its own, if that's what you want to produce.