...because Google was being very arrogant in their stagnation of source tools and community coding infrastructure.

It's easy to say GitHub is killing it now, but back then (2008), GitHub was slow, buggy, and could have been eclipsed by anybody with the drive and focus to run them into the ground. But, GitHub had (has) those wacky overachieving social coder founders. The entirety of Google doesn't have a chance at even recognizing people like that within their ranks, much less (these days) pulling them up out of the muck into leadership positions to create viable competitive products.

It points to a great reason behind the G+ failure too. If they couldn't make a viable social service for nerds—their core in-office demo—what is the chance they can make a social service for the planet?