It was always impressed upon me (heavily) that the term "art" was bidirectional.
If the observer thinks the piece is art, then it is art.
If the creator considers it art, then it is art.
My guess as to why these brash and controversial statements are surfacing has two words: Rotten Tomatoes. With the proliferation of social media, anyone can be a film critic. The quintessential movie critic days have long since passed, and there just isn't place for Ebert anymore. He needs to let it go, get out on his front porch and tell kids to get off his lawn.
Just my $.02.