The very same people who trashed Rockwell as "too illustrative" were hailing de Kooning and Pollock for their "genius."
The people you refer to run the "art" business in the very same way that the MSM runs the "news" business. In both cases you have an insular clique with utter contempt for the interests of those outside their ken.
If you’re talking about overtly political “art” that relies more upon the bio of the artist than any aesthetic assessment of the work (Mapplethorpe, et al.), I’d agree with you.
However, there are subtleties that people who have not studied the matter in depth will not necessarily recognize, in color palette, materials, composition and choice of subject matter that validate certain works of art that are difficult to grasp for the general public.
Music and literature go through the same vetting process and generate controversy, but not nearly to the level of visual art. People who know nothing about the subject have strong opinions about what they “like” and what they don’t like. Others judge paintings by whether or not they’ll go with their furniture and draperies. These are perfectly valid reasons to buy something if an individual is so inclined. But, it doesn’t make it good and it doesn’t make it “art.”
I’m reminded of a Western Artist charles schreyvogel. He did a painting and the critics savaged it and him unmercifully.
Then that painting won a prestigious art award. Suddenly the same critics did a turn around and lauded his work as great.