I used to work for at&t and we would see at least 35 people a day who shattered their iPhones. At that point, you can't really do shit but pay 200 to apple to fix it or find somebody on the street who will probably fuck your phone up.
Bottom line, if you've ever dropped any phone you've ever owned, and you get an iPhone, a case is neccesary. Most of you may not ever drop your phone, but the average person does, and a case is the only protection you have from fucking your phone up. You guys are acting like the phone is made of adamantium or something, and it's not.