Honestly, anyone using Github as a basis for hiring to begin with is approaching hiring with flawed thinking. Github isn't the only source for git, and git isn't the only standard for version control. Further, Github has been pushing companies AWAY from the platform thanks to high costs and other nonsense. I've seen more than one company either run a local git server or something like a local git lab instance. Using github as a metric just ensures that you eliminate anyone not using github. That includes many amazing open source devs, for example.
Except companies aren't looking for the smartest programmer, they looking for a cog to fit into a spot in the machine. In that sense, evaluation someone on how well they do on the de-facto standard platform makes sense, unfortunately.
