As unfortunate, as it is, it is also quite understandable from Microsoft's point of view. They, for security reasons, with to limit all OS upgrades to official Microsoft sites. If , for any reason intentional or non, a virus, Trojan, malware, or even a corrupted file was posted there under the guise that it was an official Microsoft update then many people could be adversely affected and blaming Microsoft ...
Then there are also potential issues with Microsoft's Genuine advantage program which forces customers to validate their copy before DL'ing updates. They really wish to force people to prove they have non-pirated OS's before they are allowed to update their copies and this bypasses the entire validation process ...
It is a nice convienance, but really I'm surprised it lasted this long before M$ shut it down.