It was sarcasm, but git itself is Decentralized VCS. Technically speaking, every git checkout is a repo of itself. GitHub doesn't stop me from having the entire repo history up to last pull, and I still can push either to the company backup server or my coworker directly.

However, since we use github.com fore more than just a git hosting it is SPOF in most cases, and we treat it as a snow day.

Yep, agreed - Issues being down would be a bit of a killer.