Everything is built from something else. Not doing the fundamental science that leads to a product doesn't mean that the product itself isn't innovative. Apple's interface elements[0] and interactions[1] were no doubt derived from elsewhere too. Getting UI elements on a screen wasn't new. Cramming a capacative touchscreen into a phone was very new.
Right, people were buying iPhones because they wanted to touch two or more fingers. Everyone was trying to make screens that can register multiple touches but Apple was the first to crack it and this led to natural success of market demanding multiple touches and they having it.
[0] https://developer.mozilla.org/en-US/docs/Web/HTML/Element/bu...
[1] http://www.billbuxton.com/multitouchOverview.html