get a good case and you massively reduce the risk of cracking/breaking anything on your phone! I think I do understand how people want to see the phone in its original glory and they feel like it looks uglier with a case. But if a phone is that expensive, personally I would always have a case on it 99.9% of the time. You won't believe how many different cracked iPhone screens I used to see in my old college, lot of people wanted to be stylish and didn't like to use cases and that's what happened.
I'd also like to know like a previous user in this thread asked, how many of you who had cracked lenses were using cases? I think it would be a much more serious problem if many of you were using cases and that still happened..