I think it's appropriate in terms of describing an attitude, but it is not so great at describing skills. "Ninja", "rockstar", "guru" and such tell me that they want somebody to show up who doesn't feel stress and is able to make the tough decisions needed to be made to make the thing happen. It also means you're willing to put up with a bit of cowboy mentality in return for exceptional performance.

Doesn't mean that the programmer is worth a damn. That's a different question. Confusion results when you confuse what's being said.

It also doesn't mean that a rockstar programmer is what you really need. But that's also a different question.