Would someone please explain Twitter to me? Twitter sucks!

I don't get it. I tweet and I follow and I am followed, but it just doesn't seem very useful or interesting. It's kind of just like setting "status" on Facebook.

This is the main page I go to. So you can see the last few updates from people you follow. And frequently the whole page is taken up by one hyperactive updater. Is there more that I'm missing?