That's the nice thing about actual software with actual versions that you actually install: it doesn't change out from under you at someone else's whim. No sane person would use a "Cloud" C compiler. Of course, GitHub is just a mashup of online backup and Facebook, so it doesn't matter if it breaks.
It's not like they broke git, or some actual important interface. They stopped syntax highlighting on non mainstream languages until new lexers can be written. What on earth would you as a customer have done if they had said, "syntax highlighting in the browser for <your-favorite-language> is going to go away in a week"? Are you going to migrate away from github? Or shrug and say, "bummer"?
Github did the most efficient thing: break it and let the people who actually care fix it.
