Gonna go with the idea that the long tail is really quite long and invisible here.

I imagine github as an iceburg. Sure, I see things like bootstrap with XXXk followers and jquery on there. Big projects! Big names! Big! Big! Big!

But what about what I don't see? How many thousands of users have private accounts? How many thousands of businesses have private github repos? I don't really know. It's a smart bet that every time somebody sees all the prestige of the big name projects, they think "Hmmm, this is really working for them; Could it work so well for me/my project/my startup/ my enterprise? I hope I can make this private."

I am just saying, sure there is a lot of shovel selling going on. But just because you can't see others digging, doesn't mean they aren't out there.