The Swype concept is what any mild-mannered engineer would come up with when faced with the problem of "come up with more efficient ways to input text on a handheld touchscreen device". Here's an idea: "Use the QWERTY keyboard except don't lift your finger when typing hurr". I mean, this obviousness can be tested empirically. Take a group of mild-mannered engineers (ignorant of Swype) and ask them to brainstorm ways of inputing text into a handheld touchscreen. How often is the Swype concept "discovered"? I would venture every time, but hey hindsight bias and all. Furthermore, there is nothing difficult (in the sense of requiring years of research and investment to solve) or technology-expanding about its implementation in software.
I'm not sure if "requires years of expensive R&D to produce" should be the only criterion for patentability. But clearly Swype, Amazon's one-click purchase, slide-to-unlock, in-app purchasing, etc. are all poor patents and hurt the advancement of the industry and consumers.