I too have noticed a prevalence of males in the ranking cabin staff roles (dark blue jackets and higher) in Business and First Class, but I did have an odd experience with a female supervisor. Last December on the SIN-BKK evening express, we had no less than six Singapore Girls quite competently and quickly serving the back half of the Y cabin on a B777-300. One or two of them were in the third-ranking color kebaya (green, IIRC), but none higher than that and no males, who were all working the front half of Y and the premium cabins. The strangest thing, though, was that a female supervisor of some sort stood in the aft part of the cabin around the galley, closely watching the Singapore Girls at work, obviously for quality-control purposes. She was definitely not in an in-flight uniform--she rather looked like a Singaporean version of Frau Farbissenne of Austin Powers fame. I can think of more subtle methods of quality contol, but the fear of crossing her would scare me into perfection, that's for sure.

As for the Singapore Boys, I'm quite content to have them looking after me for the duration.