Apple regularly licenses patents when it agrees they are valid. That doesn't make the news. Sometimes they disagree and that makes the news.
Not only does it not make the news, it's often confidential.
Why not? They 'license' plenty of things without using their brand name publically, like Gorilla Glass
Sure it is. They licenced Microsoft's Exchange protocols.
Licensing from a fellow giant who will absolutely take you to court if you don't and repurposing the ideas of small indie developers are entirely different things.
I could be wrong, but I don't think Apple has a history of violating patents from practicing small software developers. Seems like they're pretty much only sued by patent trolls.