On the flip side, I knew an attorney who turned down a great candidate because the guy showed up to the interview driving a mercedes (which - really? what does he do with the maserati drivers?

) and wearing a nice watch. His reason was that he wanted "hungry" associates - so he hired the most brash, unprofessional, tasteless guy who would have been a shoe-in for that pawn-shop reality show ... and couldn't figure out why his clients were unhappy.
So it works both ways. People hire based on their own feelings, insecurities and issues - most of which they're completely unaware of, or would never admit to. It's not a science. Hiring is an area of almost absolute power, and you know the saying about absolute power corrupting absolutely. It's a chance to see what your future boss is really made of (and for the record, most of them ARE fairly decent people).