It's a stupid response to avoid the fact that all the major clients already SUPPORT doing backup.
Origin allows you to move data, when you install the game it just checks the content and install it without downloading it again, provided you copy the game exactly as it is.
Ubisoft client does exactly as Origin.
Steam provides a full backup system that works perfectly fine and you can even do like Origin and copy the folder which will prompt Steam to "discovering existing files".
GoG has the option of a direct download and an option to "download the installer" which will be good for installing on multiple machines if you need to.
So, WHY is Microsoft the only one not caring about this?. How dumb can you be? Is it the same to download an 80GB game through a 4Mbits connection just because you want to play it on another PC than just taking your USB-HDD and making a backup?.
They tried to port the Xbox One store into PC but they completely forgot that the PC does NOT BEHAVE like a console, and I have the Xbox One so I know what I'm talking about.
PC Gamers need the backup option, we can't rely on a massive download each time we need to reinstall the operating system, it's dumb. Each time someone replies "redownload the game" is new evidence that people near silicon valley ignores the rest of the world.