If you walk into our home, anytime during waking hours, the television will be turned on. Generally tuned to Cartoon Network or Nickelodeon. You may, during certain times of the day, catch it on Animal Planet, or the Science Channel.
There are a lot of statistics regarding children and television. I've seen the studies, but I've also seen first hand how my children handle watching the boob tube.
Yes the telly is always on, but the chances of catching my boys statically watching, and doing nothing else is going to be slim. Often times the television is just providing background noise for their other activities.
If you haven't noticed, more and more information is being thrown around at people. Even billboards are turning into picture tubes, playing mini-commercials while you drive by. The information age is in full swing, and I think it's critical for children to learn how to tune out the unimportant, while at the same time being able to listen passively for things that pique their interest. This is what my boys practice daily.
Sure, they may spend the occasional hour mindlessly tuned in, but they spend far more time running, playing, drawing, writing, reading and engaging the people around them.