GitHub as a recruitment filter

When I was at QCon San Francisco, I heard a talk about recruiting software engineers, and one of the points of the speaker, was that you should check out the GitHub profile of the candidates. This is something I found a little worrisome, not only because I don't have an (active) GitHub profile, but also because it seemed to me that this would lead you to exclude a number of good candidates.

I am all for open source, but I don't spend time on them, since I have enough work to do on work and non-programming related projects for me not wanting to add more to it. Does this make me a bad programmer? Perhaps. But probably not. Currently I am mostly doing business analytics (i.e. trying to help define the needs of the customer), but when I am on a project as a programmer, I tend to average more than a full days work each day - I could spend the overtime on open source projects, but I frankly don't see how this is a better use of my time, in the eyes of optential future employers.

There are also numerous other reasons why using GitHub profile as a recruitment filter is a bad idea, and there are two great blogposts that explains this:

Ashe Dryden: The Ethics of Unpaid Labor and the OSS Community
James Coglan: Why GitHub is not your CV

They should be read in the posted order, as Coglan's post is an expansion on Dryden's post.