Everyone who has an Xbox 360 Live account has an avatar, but not everyone spends time dressing them or buys accessories/outfits for them. Which group do you fall under? Have you spent any time and/or money personalizing your avatar?
I thought it was really stupid how Microsoft was just copying the Wii's Miis when they first came out, but now I am used to them. I have never, ever bought any clothes for my avatar and probably never will (seems pointless). I have spent some time making it look like me and dressing it in clothes similar to what I would wear given the limited free choices, though.