With a passive activity like watching TV you have TV in the background while doing other things. Hence my like of what I call junk food TV. It's TV I can half pay attention to. So TV is on while I a doing other things.
Writing takes way more attention that that. So much so that if I am writing up an email or a blog post I completely lose track of anything happening with the background of the TV.
And my brain can't do that. I've occasionally tried to play poker while watching a movie, and I either hose the poker game or I don't really see any of the movie. I don't really like the distraction of the background noise, either.
Something snapped in me last year, I think it's when we dropped HBO after they cancelled Deadwood and the Sopranos finished. Suddenly I just couldn't stand to watch television dramas. My wife would say, "Hey, the season finale of Mad Men or Battlestar Galactica is on the tivo" and I'd be just like, "Eh, who cares. Some artificial drama that will cliffhang until next season. When does it ever end? And when it ends, who cares? It's all made up."
In contrast to shirky's comment, I burned myself out in 60 days on Stormreach, a sort of World of Warcraft. I played one night with a buddy for 4 hours, and said to myself, "I just wasted 4 hrs of my precious life getting a little pixellated version of an axe. WTF waste of time is that?"
Poker, books, the occasional movie, playing with the kid, backgammon with the wife, listening to podcasts like this american life or radiolab, that is all that interests me. I'm burned out on made up drama.