>> The actual best developers mostly have little or nothing to point to on GitHub. You might find this shocking but many of them don't even know how to use Git at all.

It all goes in circles. As soon as Github (GIT in general) becomes adopted by the majority of enterprise (already happened probably) we are gonna see something else which is "cool". Something else, smaller, simpler, cooler gonna attract the next wave of programmers. I am sure there is a great space for innovation.