Good take on the matter and I think you have good points there, but to be honest, I think you are lacking a definition of "art". Most of your argument is based on a separation of "art" and "non-art" that is either vague, biased, or based on specific art forms (such as Scorcese's and Ebert's view on Cinema).

A quick research on the various interpretations of what "art" means quickly intersects with the idea of "human expression & creativity" - which is pretty much present in whatever summer block buster movie or straightforward action oriented game. It is also present in the games cited in your text and it is a huge stretch to assume that no one involved in those productions was not putting "artistry" effort into their work. The level designs, concept ART, 3D models, narrative - pretty much all that is visual-creative-expression in those examples are clear examples of art.

Although I think it is not your main point (but probably is Scorcese's and Ebert's), or even your intention, this discourse that tries to separate "art" and "non-art" is just there for one thing: downplay what is popular as inferior in a clearly elitist point of view that separates the "regular audience" from the "intellectual beings" - the guardians of truth. We, common folk, have nothing to gain from it besides being pushed aside.

Moreover, I disagree that "depends on the game". If some one does not feel like calling "Iron Man" or "Pretty much any Nintendo game" art-pieces, that's fine. We are entitled to personal opinion. it does not change, though, the effort of the many artists involved in the process - nor it reduces the quality of it compared to other "accepted-as-art" pieces.