2 things. 1) many people who use GitHub do not understand distributed VC, and treat it as a central repo. GitHub is trying to do education here, and has published the disaster guide sant0sk linked to.
2) GitHub is more than just a git repo. It's a social network. People use it to find code, explore code, paste code snippets...so when GH is down, a lot of interaction can't take place.
2) GitHub is more than just a git repo. It's a social network. People use it to find code, explore code, paste code snippets...so when GH is down, a lot of interaction can't take place.