Using the timezone was Github's way of easily getting the right orientation of the globe for the viewer's location. In my case (and I'm guessing everyone in the southern hemisphere) that doesn't work.
It looks like it starts showing the globe North of about 5° South, which would get 89% of the world's population. Pan down just another 3° (include the population centres in Indonesia, without sacrificing anything in the North) to get to 94% of the population. Of course, Github's user base may be distributed differently.
Aren't most globes oriented that way for display though? They copied the normal angle used for physical globes so it's instantly recognizable I suspect.