You are absolutely correct, old man jones. It is not the data on the iPhone the fbi is after, it is a backdoor for all iphones. The current problem could easilty be solved by Apple and even McAffee, by putting a team of apple developers in a room and giving them the iPhone. They could surely hack the iPhone and retrieve the data.They happened, and all that spying illegal and legal didn't help one bit to stop any of it. So the spy agencies are trying to scare us into giving them even more secret power we must never question (and can't question) to spy on everyone, just like the Stasi had. Did they keep the wall from falling? Secret police oppress their society, they do not defend it.
What thwarted plots? Do name some. As for the present case, there's already all the evidence needed to convict the shooters without breaking into their iPhone.
But that is not what the FBI is after.