Never mind even governments.
The most basic reason why encryption exists is NOT to stop governments from looking at my text messages. It is to stop various criminals and bad guys from gaining access to my phone.
If Apple makes iPhone security weaker for the government’s sake, it makes it weaker for everyone. There is no reason any of a number of well motivated criminal groups couldn’t figure out the backdoor and start using it to hack into your phones.
Right now, I’m pretty happy knowing that if I drop my phone somewhere, people wouldn’t be able to unlock it and gain access to my banking info or any of the dozens of accounts I’m logged into. And that is the primary reason why the encryption is there.
There is another excellent post on medium talking about this topic. It compares encryption to curtains: https://medium.com/@sweis/when-curtains-block-justice-142cbd0f3f34#.4dkcrljyi