I disagree, Gaffer. Just the knowledge that it can be done is bad for Apple and their customers' privacy and security. Apple has stated that they absolutely do NOT have the key to get into their customers' iOS 8 and later devices. If Apple were to unlock this iPhone 5C running iOS 9, they would tell hackers everywhere there IS a way to do it. Those hackers would not rest until they found it.
I guess we disagree then. To me it is no different than getting a court order to open a safe, safe deposit box, open a mailbox.....
The difference for me is DOING it for the FBI and giving them the tools and software so they can do it any time they want. I don’t support giving the FBI the tools to use any time they want.
A last comment on your iOS 8/9 and hackers. If Apple has said there isn’t a way, and there IS, how safe does that make you feel about their claim? Is that what you call ‘security?’