While a good example, that was in 2015. There haven't been very many (or any?) public challenges since - which does make one wonder...

Apple could simultaneously backdoor their devices while also keep them secure from anyone but the government with a warrant. These things are not mutually exclusive.

The China precedent is troubling - to say the least.

You cannot backdoor a device in such a way that only 'certain' people can access it. Once that door is there, people will find an exploit it. The only way to be completely secure is never build the door in the first place.