Well has anyone considered that the whole business of GRADING movies as you put it is a sorry one? There's nothing worse than a "Top Ten" list of movies, nor more tedious than people who rate moves in terms of a percentage score or an A-F rating.

The quality of films are incommensurate and cannot be measured as 5 out of 10, or 72%, or B+ or whatever. One of the most inane questions to be asked is "What is the best film / your favourite film of all time". Only a person who had seen very few films could answer that question decisively. Anyone who has seen a good number of movies will appreciate that there is no single best film (either objectively or subjectively).

The answer to the art / escapism dichotomy lies in discovering the predominant reason for sitting in front of a screen for 150, 200 or however many minutes. I would venture that, while there are moments of genuine artistic class, the general part of a film is enjoyed through escapism and not through artisitc appreciation.