they used to be able to download a patch, archive to CD and when the buggy game code shagged their computer they could re-install it up to a playable state
And you can do the same thing with Steam apps. Backup the directory (yes, you can backup just the changed bits too -- that's what incremental backups are for! Shock, I know.) and then just copy the entire thing from CD/DVD back to your drive if you feel the need to reinstall the OS.
without waiting 3 days (cause Steam is on its arse again)
And when was the last time Steam was down for anywhere close to that long?
4 hours (transit time)
Your own damn fault for not backing up then. And don't try to say "well I shouldn't have to back up" because you just said you'd be archiving the patch to CD. This is no different.
Don't like Steam? Fine. Don't use it. Don't play the games that use it. Vote with your pocketbook. But quit making inane, incorrect arguments that only show your own ignorance.