They'll have to invent something really new or have an uphill battle, because GitHub now relies a lot on network externality. In simple words, it is the effect

They'll have to invent something really new or have an uphill battle, because GitHub now relies a lot on network externality. In simple words, it is the effect that you chose a popular network for the number of projects on it. I do submit bug reports to projects on BitBucket and GitHub, and not to private bugzillas/tracs (I'm tired of registering and confirming every time.)