I agree completely. I meant I expect many people have watched closed source projects die before they're released or be abandoned after release, but that is hard

I agree completely. I meant I expect many people have watched closed source projects die before they're released or be abandoned after release, but that is harder to measure in aggregate because it's much less likely to be seen. So the author is wrong to compare all software on Github to closed source software he's heard about. Those "measurements" are completely different.