The thing is.. you don't have to mention the rest because ALL THE OTHER stores support doing a backup and restore in some way or another.
Origin - lets you copy the files, will scan the contents if it detects them and start downloading if something is broke or says "installing" if its all good.
UPlay - will display discovering content and even show you the "discovering speed" while the hdd works and after that it displays "installed"
GoG - will display discovering content and shows when it's installed just by pointing the files to the install path.
Steam - will let you discover files as the rest or even do a full backup with an installer.
So... It's not that Microsoft is not supporting an oficial backup because Origin wont, it's that it WONT LET YOU DO any kind of backup and it's the ONLY STORE that won't let you do anything with it.