Not sure he's accurate when referring to Github users, but I think he's probably not far off for git users in general. I mean, most git users aren't the people hanging around here. I don't see a reason to expect that more than "the simplest thing that could possibly work" to be commonplace.

When I use git (I tend to use hg more because it's more friendly for Windows projects, where I often find myself), I generally work on master for personal projects where I'm the only committer. It's easier for that use case. Branches are primarily valuable, IMO, when you have multiple people bashing on it at once.