Why isn't the patch available for DL 1 week prior to going live?

I don’t get it, why don’t you release the patch files a week ahead of it’s live date to be downloaded in the background similar to Blizzard games.

Instead of throttling everyone’s downloads and making it painstakingly difficult to download the patch on the same day.

Seems like nonsense, either do that or upgrade your severs to be able to handle the capacity.