Terrible name though. "Genius", ugh.
To someone with a genius IQ, especially one who joins Mensa solely for the ego boost... Yeah, "Genius" is a terrible name. The existence of "Geniuses" with sub-genius IQs clearly devalues the entire notion of "genius."
But that's not the point, genius. To the vast majority of tech product users,
anyone who knows how to solve their problem is a genius. They're not going to ask for an IQ score before declaring, "Thank you, you're a genius!"
The average person has enough common sense to understand that "Genius Bar" is a marketing term, not a promise that they'll be working with an MIT PhD.
As marketing terms go, I think Genius Bar is quite brilliant, a whole lot more evocative than, "Repair Shop," or "Tech Support." It suggests a quality of service that will be above normal expectations, that a solution will be found. To the vast majority of Apple customers, the name seems to work brilliantly. They flock to the Apple Store for the Genius Bar experience, they consistently rank Apple tech support as the best. The term is as inextricably bound to the Apple brand as Macintosh, iPhone, iPod, and iTunes.
If you do know more about Macs (or iPhones) than Apple's Geniuses (who are not hired for their IQ scores, but for other characteristics, social as well as technical), you are in the minority. Feel free to boost your own ego by testing your knowledge against store staff, and be sure to come back here and boast about it.