Not the original poster but from my perspective it's the lack of tools in github to manage the proliferation of repos. I'd like to categorise them when I'm browsing my own repos and expose those tags to other people: my hairbrained experiment repos, my serious OSS efforts, my fork-to-keep-a-stable-version-of-some-remote-project repos...

I could do something like that by creating a load of organisations but it'd be nice if there was a simpler way. Gists provide a very primitive way to divide things up, but at least it's something!

Yes, that's a good point. Although gists too is a flat list I think. But at least with gists and repos we have two flat lists.