I've used gists since the beginning and didn't even realise you could treat it like a git repo.

While a lot heavier but also good, GitLab CE/ EE have "snippets", basically gists, that are backed by git repositories. Same UI as GitHub gists, same comment/ visibility/ share system.

There are plenty of other systems to do this with. Gist's value proposition seems orthogonal to its Git integration—more to do with its UX.