That's a good observation. Facebook is becoming like TV in that lots of people spend a ton of time with it even though almost all of its content is trivial, while really productive people tend to spend relatively little if any time with it.
I never signed up for facebook. But today I'm pretty much the black sheep.
Email, telephone, webpages, those existed long before Facebook. It feels like millions of people think that they are enlighten about internet communications when then become regular Facebook users.
I don't like to base my social interaction on a private closed network/service. I prefer distributed and open technologies.
This story posts on a Saturday night. Also pro-facebookers aren't likely to care so much about yet another usage poll. The ultimate poll is Facebook's site stats.