"H. Smiggy McStudge" may be talking about modern art, jazz, and literary fiction, but the tendencies he describes - for example, the refusal to actually engage the common man - are also emerging in the sci-fi/fantasy fandom as certain folks scramble to prove their highbrow bona fides. This passage in particular seems especially relevant to our interests:
We encouraged painters to become more and more interested in the weave of the canvas, the weight of the brush-strokes, the plasticity of the paint; less and less interested in what the painting was about. The ideal picture was not a window on reality, but a sculpture a quarter of an inch thick; and for the most part, I am happy to report, the new art was as shallow as its medium. Painters stopped talking to their audience through imagery; now they only talked to one another about texture and impasto. We killed that art in a generation, and despite valiant efforts to revive it, it has remained safely in the grave. You can tell this is so, because whenever a painter dares to produce a vivid representation of a real or imagined scene, all the critics hiss and sneer and call him an illustrator: the worst insult in their vocabulary. The fear of ostracism (and of losing grants and gallery space) keeps the artists in their place; and their place is as far away from the viewing public as we can put them.
Beginning about 1940, we played the same trick on the jazz musicians, with great success; it took us just twenty years to kill jazz, as a creative medium accessible to the people, stone dead. The game was the same: make the artist so interested in technique that he forgets all about his audience.
And so far, such a game has been diabolically effective wherever it's been played.