Resale, possibly other reasons. Why are you worrying about what others do with their stuff? If you don't get it then don't do it.

Yeah, my spiteful ranty point is made nonethless.

Can I suggest to Apple that they stop ruining the iPhone with their mirror-finish aluminum back? Every time I get a fingerprint on an Apple product, I feel like I've ruined a piece of art. Without a case, it gets scuffed and destroyed. With a case, I can't appreciate the design I just spent exorbitant amounts of…

Agreed, but eventually the lens get scratched enough from laying the phone on it's back that the picture quality starts to suffer.

Hah! Right you are! You win this time, komododave, but this is FAR from over.

The only reason I use a case on my 4s is because of the camera lens. I found the camera lens to get scratched quite easily on my iPhone 4 that didn't have a case. Until Apple recesses the camera lens, my 4s will live in a case.

Technically, the iPhone has a silicon case.

BookBook for my iphone 4s. It's survived 4 or 5 drops onto the concrete steps from 5 feet or so without a scratch and it serves as my wallet too, yes I have applecare. my iPad 2 I have a smart cover and dropped it from 4' onto concrete, the smart cover took a thrashing and the corner of my iPad got dented but the…

Not to mention the antenna design on the iPhone4, they gave the rubber bumpers so your skin wouldn't contact the antenna and cause a loss in signal....albeit a minor one.

The iPhone was not designed to be used without a case. Both faces are glass, and the glass is raised above the metal frame (not inset) and it only has the tiniest plastic bezel possible around the edge of the glass.