I agree with you personally. But find that not everyone wants to communicate clearly. Some people have made a career out of impenetrable communication.
Not the parent poster, but: think of speed bumps. They force you to slow down and pay more attention to the road.
Some writers, particularly post-modern ones, aim at the same thing. By forcing you to read their works carefully, you'll (in theory) be forced to think about them more.
That feels like the author is saying “I’m so clever you need to be told when to think about this,” whereas i would prefer to think at my own pace, without deliberate obfuscation, thanks very much.
If it’s a work of art, fair enough. If you’re trying to explain or argue something... then you’re probably hiding the holes in your argument or trying to sound smarter than you are.
I don’t think this essay precludes that either, the 1% of 1% of books that are made better by being Proust rather than Vonnegut. And the chances of you being Proust are essentially zero.