In case you hadn't guessed it already, using the iPhone in the cold is not fun. Right now it's 31 degrees F in NYC (feels like 23 degrees F) so exposing your hand and trying to dial might not be the user experience Apple was looking for.
If you have gloves you have to take them off and dial as quickly as you can. If you don't wear gloves (me neither) your hands are already cold- so now trying to send a text message with your hands exposed and no tactile feedback.
I don't know what it's like in Cupertino in the winter, but it must not be that cold. To be honest, I saw this coming as soon as I saw the first official image of the iPhone, but that was in what- June? Maybe May? It's hard to remember just how cold it gets when you are getting ready for the summer.