I don't understand how rockstar became synonymous with highly competent/productive. It's almost the exact opposite of the accepted meaning.
Second, one can't rule out the possibility that "rockstar" started out as irony, or even an insult, applied to a specific handful of people who later became famous and carried the word along with them. That's what happened to the word impressionist, for example, which was coined by a derisive outsider as part of an insulting review but then got adopted by the Impressionists themselves and eventually became a standard term for a specific flavor of artist.
Having said all of that... There are lots of traits of actual rockstars that the word "rockstar" is meant to convey:
You're looking for an artist, not a bureaucrat.
You're looking for someone who attempts to connect with an audience, who understands that their job is communication.
You're looking for someone who shows evidence of patient and diligent practice. Though the Sex Pistols might be the exception that proves the rule [1], you don't become a rockstar by sheer luck, or charisma, or the right hairstyle, or by taking heroin and smashing up hotel rooms. You need talent. You have to practice a whole lot. Generally alone, and in obscurity, for little pay, because you take joy in the practice of your art, and because you are a forward-looking person with big goals.
You're looking for someone with big goals, someone who aspires to at least a little more than the average session musician. Someone who is going somewhere and can inspire others to follow.
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[1] Remember: If progressive rock had never been invented, the Sex Pistols could never have succeeded: AFAIK the first wave of punk rock was a reaction to other genres. And it was extremely temporary... within literally weeks the punk movement was dominated by people who had some practice, if only because the early bands inevitably got some practice. ;)
It's still stupid, lazy phrasing IMO, but that seems to be people's meaning.
You know why? Because it's easy to make people think you're some kind of misunderstood genius without having any kind of valuable work whatsoever.
I.e. you just need to be a good salesman when selling your image to others.
I love DHH, but how many engineers and computer scientists have pushed the state of the art of our field much further than a web framework can ever do and without being viewed with awe by others?
Here you go ... http://www.google.com/trends?q=steve+jobs,+alan+kay,+steve+w...
All four of them are rockstars. Only one of them wouldn't be where it is today without the other 3. Guess which one.
Jonathan Ive.
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"[Steve Jobs'] return to Apple in 1997, after it purchased NeXT, is now the stuff of legend. In the design department, Jobs saw the work of a young Briton called Jonathan Ive and asked for a meeting. Ive, underused and ignored for a year, turned up with a resignation letter tucked into the back pocket of his jeans. He left with instructions to unleash his talent. The result was the iMac..."
(Source: http://www.time.com/time/business/article/0,8599,1976935-1,0...)
Are you kidding? It's incredibly difficult to impersonate a rockstar. Even I, who have not watched a single minute of American Idol, know how to tell a true rockstar in thirty seconds: Auditions. You hand them an instrument or a microphone and tell them to perform.
And a rockstar needs a portfolio and -- if possible -- a fanbase [1], and these are also hard to fake. Evidence on Youtube suggests that Stefani Germanotta had a lot of musical talent and intelligence as a sophomore in music school, but she didn't become a rockstar until she'd developed a persona, adopted a stage name, released some tracks, and sold them to enough people. Real rockstars ship.
Analogously, we all know that when a programmer comes through the door claiming to be a rockstar you have to insist on seeing their portfolio and watching them perform. That's what all the discussions of the interview process are about.
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[1] In practice, the software metaphor rockstar really means something more like "aspiring rock star"; it doesn't necessarily refer to a programmer with a "fan base". If you actually want to hire Linus Torvalds, or Lady Gaga for that matter, you don't put out an ad asking for a "rockstar". You phone them up personally, or phone their agent.
"Rockstar" definitely carries the baggage of being highly-associated with douchebags and prima-donnas. But it's not all negative.
The recording industry has used the same manipulation techniques to screw ingenuous people for ages.