But Apple sees a problem in that. When they do it, they consider it to be perfectly fine and give it names like 'inspiration'.
But when others do it they act like they were the first ones to bring it to earth and others are 'stealing' it from them.
As a software developer, I'm really tired of people who keep acting like the iPhone wasn't innovative because smartphones existed... yeah they did. They ran on shitty embedded kernels, were starved for resources, and were useless for anything but clunky caricatures of desktop software. My Nokia N73 'smartphone' needed 10 seconds to go from opening the lens cover to being able to take a picture. And you know what? It still sold, because they all sucked.
iOS had the entire mature OS X stack in it, with Quartz/PDF, OpenGL, CoreAudio/Image/Video, ... The innovation is in how that was used to provide the total package, not in the features you tick off on a list. And the fact that people like Steve Ballmer dissed and derided it on features, only to adopt the exact same strategy years later for Windows Phone—down to the limited feature set of the first Metro release—shows that the industry really did not get it at all. It has nothing to do with shiny rounded rectangles, and everything to do with what that rectangle does and how.
The best sign of a revolutionary product is that it immediately becomes so self-evident that nobody can imagine not having thought of it themselves.