That and patenting the finger swipe are two of the most egregious hypocrisies of Apple's patent lawsuits. However it's really the USPTO that is to blame. IIRC if you're big enough you can just bully the patent office until they acquiesce. USPTO needs to learn how to say no, even to big corporations.

Which makes me wonder: Imagine if USPTO published statistics that enumerated patents that a company applied for and were turned down. My guess is Apple has never been told no.