Why iPhone Cases?

The folks over at PC Mag recently wrote an article on the 10 Coolest iPhone 3G Cases. I'm asking why? Cases for phones and mp3 players are completely pointless. They usually make the device much uglier than the manufacturer intended, and they don't "protect" the device very well. I bought a hard plastic cover for my iPod several years ago, and it was completely useless. The plastic cover for the screen got many annoying scratches that made it hard to view videos, and the back of the case scratched up the stainless steel backing of the 3rd generation iPod. The case itself did much more damage to the iPod than what I would have done normally using the device! It also was a clear plastic case, which was much less attractive than the iPod's original exterior, and it significantly added to the thickness of the iPod. Basically what I'm trying to say is don't waste your money on pointless cases for your cell phone or mp3 player!