I use Github, but mostly just for work. For example, in one case I was revamping a legacy product entirely, and the customer needed it backed up somewhere. They didn't have a github account, so I made a private project and gave a couple of them access. They will never use that access unless I get hit by a bus, but it is a quick and easy way to both make a secure backup of the code, and give the customer peace of mind that they have a copy of the latest version of that code if they need it (presumably to give to the new programmer, along with a short story about how the last guy got hit by a bus and they don't know how it works but here's the code).

I suppose it does provide some evidence that you know something about programming, but to be honest I've never thought oddly about somebody who has no Github profile. Talking to them about coding for a few minutes will give you a better idea of that.