I'm surprised you don't think there could be any more to art history/criticism than either "Look, it's a picture of a duck" or postmodern babble.

I am perhaps a bit oversensitive to the word "understanding", which was what I was mainly pointing at. Every time I met this word in connection with art or literature, it was someone trying to impose her aesthetic preferences on me while signalling her superior cultural sophistication. I am not completely ignorant about history of art, I paint as a hobby and usually spend more than fifteen minutes in a gallery. But all my school experiences with learning to understand art or literature or music - as opposed to learning how to draw or write or sing - was a boring exercise in snobbery.

Even with the uniformly blue canvas, looking at it can be an interesting opportunity to learn about who painted it and why they thought they were doing it (even if you don't agree with their rationale or take it at face value), and maybe spend ten seconds trying to see it through their eyes. Even if you ultimately conclude that it sucks and that the painter was stupid and wrong about everything, it's not less enjoyable than just seeing the blue canvas and spending ten seconds being baffled or bored by it and then moving on.

This can be said about almost anything. Look at a chair, a railroad track or a dog's leash and ponder about the maker's intentions and motives. Almost any product of human effort is worth ten seconds of thought, usually more interesting than with a blue canvas. Singling out paintings for such an argument is privileging the hypothesis. And remember, modern art advocates even don't tell us to think ten seconds about any object we happen to look at. They tell us to spend much longer time thinking about objects classified within the quite arbitrary category "art", pretending that those are especially interesting or important. They aren't. Rothko's thoughts about colour fields on one of his paintings are no more interesting than my neighbour's thoughts about the shape of his new flowerbed; after all, both are of comparable complexity and take about the same time to complete. I have had discussions about the blue canvas (I remember neither the author nor the name of the painting) when my friend said that I can't pronounce the canvas worthless - perhaps the choice of the exact colour was the unique act of creativity and the precise uniformity reflects the author's genius. It's silly.