From a review of one of Bill Viola's latest video art installations Martyrs:

Viola was one of video art’s earliest exponents, and is now one of its most popular and critically divisive. He was the first video artist to have a retrospective to himself, at the Whitney in 1998. When Ada Louise Huxtable saw a work called The Crossing there—which, with effects very similar to some of those used in Martyrs, shows a walking man being consumed by falling water and by flames—she wrote in The New York Review that it was “an unforgettable image” that “can be taken as a morality play or a stunning piece of visual theatre.” It’s a combination of mystical ideas and aesthetic drama that perhaps explains why crowds flock to his shows. The New Yorker‘s art critic Peter Schjeldahl, though, is one of a chorus of dismissive voices: “unremittingly, emptily pretentious” and “a master of special effects passed off as spiritual epiphanies.” One of the most perceptive remarks has come from Roberta Smith. When she reviewed his Whitney exhibit for The New York Times she wrote that “it may be that Mr. Viola is better in small doses, in situations where you can contemplate his work without having to walk into another Viola.”
The reason for that is a mixture of portentousness and pace. Viola makes most of his work in slow motion, and a whole exhibition is agonizingly languorous. Most of his videos are very long, and the climaxes, when they come, are often vacant and predictable. Going Forth by Day (the title is drawn from the Egyptian Book of the Dead) is a huge five-video installation. One part shows a team from the emergency services packing up their kit after a flood in the desert, while a woman, wrapped in a blanket, waits by the water. Nothing much happens and eventually they all go to sleep. Then a man rises out of the water and up into the sky. It begins to rain, then the sun comes out and the people wake up. The piece lasts more than half an hour.

I enjoyed the first Viola exhibit I ever saw when living in New York City, slow motion high definition video has a hypnotic fetishization of thin slices of time that is like a more luxurious version of an animated GIF, but I empathize with Viola's critics in the semantic emptiness of his images.

With a proliferation of high resolution displays in the world, perhaps an artist will come along who makes this type of slow video art that can be enjoyed as background to your life rather than as a cultural luxury you have to take in at a museum in one focused visit. Something like a revival of the screensaver. Ambient art.

I wish I could buy a copy of Christian Marclay's The Clock and have it playing on a display in my apartment 24/7. It features so many images of clocks and watches that it really is a clock as art in the purest sense of the expression.