Washington's own seminal art BLOGger, Tyler Green has a very interesting and eloquent article on artnet.com.

Green makes an interesting (and valid) point about the fact that video art demands, and sometimes steals time from the viewer, as opposed to the viewer deciding how long to look at a painting or print.

It's true! In fact, regardless of the fact that 99% of most of the "video art" that I've seen are essentially rather forgettable artsy home movies, even the worst of them seems to have an invisible ability to keep the viewer plugged in watching. Even in sleepers like most of Tacita Dean's videos, one keeps a vigil, perhaps hoping that something interesting will eventually happen. At the other extreme, in the classical pre-video ancestor of video art (known then as "movies") Un Chien Andalou Buñuel and Dali­ have disconnected scenes that make no sense and yet glue the viewer from beginning to end.

Example: a few years ago I recall seeing a video at a Corcoran exhibition; I think it was a student graduate show. In the video, two girls, wearing large goat masks were butting horns (like mountain goats do) over and over again. Even though it was a repetitive, and after a while boring motion, I recall spending more time than planned just viewing it. This experience has repeated itself many times (before and since) with video art.

Why?

Green gives us his opinions as to why. And they are good observations. I also think that the fact that we are very much a television-obsessed society, and (as Harlan Ellison noted in the 60s), the glass teat is above all adictive; we have no choice! It's on a TV screen or being projected as a movie and thus the mind goes on automatic: one must watch.