Because there's shit all else to do here: Don't have my own ride, so I can't go to the usual spots. Don't have any new / next-Gen consoles (besides the Wii, but that's in the family room so I have to be home alone to use it anyways). Last new game I got (before the one at the end of November) was in January, and it was one I had already played a few years back. I haven't managed to snag any good books recently. No-one around my age / worth talking with lives within walking distance of my home.
There's nothing like a bowling alley, hobby shop, etcetera within walking distance of my house. Maybe, maybe I could walk to the Comic Shop in about half an hour / 45 minutes, same goes for a Gamestop, but that's it. I'm not about to walk 30-45 minutes to mingle with geeks when I can do such online, and I'm not going to walk 60-90 minutes to-and-back to look for games the shop may not even have.