I buy case/film/bumper just to protect my iphone. If I spend 100 dollars on the case, I am not sure which one should be protected. I would like to have something that I can easily get ride of if there is a damage. Besides,if I can afford 100 dollars case, I would just let my iphone to be naked. I think iphone design is much better than that case. just my two cents.It's called personal choice. It's the same reason some of us spent twice this much on a case for our ipads.
I think it adds a very cool industrial design element to the iPhone. I also like the design of the IP4 better then all others but feel it's not going to protect from much in the event of a fall.