But yes, if GitHub is down, then your workflow is going to change. We're hoping to close that gap down the road, but having a way to continue pushing and pulling with collaborators with a very quick setup seemed compelling to us. Not to mention the benefits that decentralization itself brings.
The vast majority of git users tend to agree on one "origin" remote and 99-100% of their pushes and pulls are to/from that remote. So git, in practice, tends to be centralized when it comes time to collaborate with others. We're trying to re-decentralize that aspect while accommodating the convenient workflows we're all used to.