This is a fallacy.
Access is access, it's either authorized or unauthorized, and it can be secure or insecure.
There is no reason a secure method of gaining access to data, on a mobile device, can not be engineered and available, when properly authorized by law. No reason at all.
We all access our devices as authorized in a secure manner every day. You can't tell me that there is no way to pull it off.
I disagree, even the "secure" manner in which we access phones can be hacked. Which is why companies are continually making it more secure.
And I also disagree that corporations should be giving back doors to governments. This goes for the US just as much as it does for China or Iran. If China issues a subpoena for someone's data should Google also give that over?