“The fact is that, although the new software may enhance privacy for some users, it severely hampers law enforcement’s ability to aid victims. All of the evidence contained in smartphones and similar devices will be lost to law enforcement, so long as the criminals take the precaution of protecting their devices with passcodes. Of course they will do so. Simply stated, passcode-protected devices render lawful court orders meaningless and encourage criminals to act with impunity.”
Lawful requests are not automatically meaningful -- fetch me the moon, explain love, find the last digit of pi, relocate this unmovable rock... You can always ask, you can punish those who resist the order, but in the end you either need to learn to accept failure, or think twice before asking for the impossible.
The argument is that at some point, law enforcement or a court might want some piece of information, but face embarrassment when naively requesting that which is inaccessible? Cry me a river! Just because information "exists", or is believed to exist, it does not necessarily follow that it should be possible (nor easy) for a judge or detective to fetch it.
A judge may someday want to know where I was, yesterday at 3:14am. Does that mean it would make sense to require me to keep a sufficiently precise diary, or wear an ankle monitor, just to enable that possible future discovery request, so the poor slob doesn't have to face disappointment? Law enforcement has always been a cat-and-mouse game, where it's expected you won't be able to get information the easy way; bills requiring it to be easy won't change that.