Apple refuses to give the United States Government a backdoor for iphones.
The FBI may use different words to describe this tool, but make no mistake: Building a version of iOS that bypasses security in this way would undeniably create a backdoor. And while the government may argue that its use would be limited to this case, there is no way to guarantee such control.
Their stance on security is one of the main reasons I got a iPhone 6 rather than going full android.
UPDATE: WHY ARE PEOPLE VOTING FOR HIM?! Actually, I heard a compelling comparison this morning, namely, he has mastered TV in a way no other politician can touch. Similarly, FDR was underestimated but his mastery of radio gave him the presidency.