The whole "Ninja" and "Rockstar" thing has become annoying, but only because everyone started using that as a symbol to indicate "programming skills", rendering the expression meaningless in the process. Thing is, Resig and the developers of jQuery are skilled. They have code to show. They have experience developing things with Javascript. Other people are using their code successfully. Those are the only things that really matter.
I don't care if they want to associate their product with "Rockstars" or "Squashed cockroaches stuffing a baked potato", as much as I don't care about the label in my clothing. And if you actually think that what you consume does not define what you are, you shouldn't either.