So it basically only restores the app and not data associated with the app. What kind of backup is that? I do not use Apple products and have a very low regard for Apple but backing up the app (who cares i can reinstall that) and not the data (that would actually be useful) sounds like a major fail on the part of Apple.
Apple normally does an EXCELLENT job of restoring your data.
Case in point: open the calculator on a Mac, type in a number, shut down the Mac, and then migrate your user profile to the new Mac. The same number will be showing on the calculator when you boot it up.
Generally, whenever you do an Apple restore, all the passwords, certificates, any authentication tokens will be missing. Apple DELIBERATELY avoids putting passwords in backups, as well as anything saved with the same storage class as passwords. Google Authenticator records very likely fall into this class - the actual storage classification would be under the control of the Google app. This is a GOOD security practice.
So if we were to apply the Apple security policy to bitcoin one backs up all the files in .bitcoin EXCEPT for wallet.dat!
No. A good security practice is to
1) Tell the user what on earth is going on and TRUST the user.
2) Provide the user with the option to ENCRYPT and back up sensitive data such as passwords and authentication tokens, with a password known only to the user and with software and encryption algorithms that are Free Software / Open Source so that they can be independently verified.
3) Not go out of your way to frustrate a user by requiring propriety software running on a propriety OS (iTunes) on either Microsoft Windows or Mac OS X in order back up files from your mobile device onto a computer. On Android I can easily back up files and ENCRYPT on a computer running the OS of my choice by simply connecting my device over a USB port with no need for special propriety software.
The minute one creates a closed ecosystem where Apple knows best and the user is not to be trusted, as is the case with IOS, then it becomes perfectly appropriate to blame Apple when something goes wrong.