Then up it to $10 and host identical copies across EC2 and Linode or Digital Ocean. Set up a git hook to automatically push from your primary to your secondary server, keeping both up to date. You now have better uptime than Github (100%, more or less) for less money than Github charges and greater control.

Yeah, but GitHub does this for, like, a hundred thousand projects. That's a lot of repeated effort if every project is going to do this themselves. For private repositories, sure, but I'm thinking of GitHub as an infrastructure provider.