Strongly disagree with your analogy here. Lots of services are capable of doing things that are against the law but in general it's the actual breaking of the law that is prosecuted.

The closest thing to what you are suggesting is the Napster ruling, where a critical part was that the whole service was only about copyright infringement. In the Github case most people are using it to write original code which is not a copyright violation so there is substantial non-infringing use.

But what I think doesn't matter. The judge disagreed with that interpretation too.