>Rock star is just a label they slap onto the job description ...
... often to arouse the ego of possible candidates.
I can't imagine why any recruiter wouldn't see the deliberate attempt at patronising candidates when they advertise "Looking for a Rock star programmer." Oh, hang on ... I know why: appealing to and strongly arousing ego is one of the quickest way to get responses.
The team matters more than the individual. Hiring with overt calls to rock stars is surely going to damage communication and collaboration with the current team.