Yeaah no, I can see how it irks people. But at least on Windows 7 (not sure about 8 or 8.1) I think there's a setting you can tweak in Windows Update to make ALL updates opt-in. But then again, with the way this is talked about, it might bypass that as well - welp.
This is an issue for people on bit-limited plans, people using cell service for Internet and people with usage caps. I have six PCs in the house. If they all get this update that is 20GB. On top of normal use. I've hit the 300GB soft cap multiple times with my normal useage, this download would certainly do it. Then you have the poor bastards in Canada that have a 100GB data limit on their bad internet...
Yeah - I'm lucky enough, I found a small Canadian provider which provides decent internet with no data cap for not an absurdly large amount of money. It is a big issue over here though.