"Rock star programmer" just makes me think diva, someone who is hard to deal with, because they think highly of themselves. Generally these people are not awful. They are either average or good, but they normally not good enough to put up with their pride. "Rock star" also makes me think of programmers who subscribe to the latest trends.
Would you call these people "rock stars": Dennis Ritchie, Brian Kernighan, Rob Pike, Larry Wall, Linus Tovalds? The good programmers don't make me think rock star. They make me think expert, master, craftsman, or journeyman. In other words, someone who works quietly, turning out software that quietly does the job reliably.