No one is claiming the idea of button-free phone; not even Apple. What you mention as the UI/UX experience is what Apple is mostly suing for. I don't claim for it to be right or wrong.
What defined the iPhone was not the hardware but software and that is what Apple is going after. Samsung is suing over FRAND patents which is something else entirely. Apple's not suing over Samsung over what they asked them to build.
This patent nonsense that exists on HN has really got to stop. It has affected very few except the claims by Lodsys. Do you really care about the brinksmanship that is conducted by two giants?