Indeed, I think the analogy hides circular reasoning - OP simply assumes what she wants to prove (men have a steady rise to the top).
Just looking at two other comment threads today - the guy on the doomed project and the guy sacked from Facebook within his first six months (https://news.ycombinator.com/item?id=5784751 and https://news.ycombinator.com/item?id=5785759) - I have an alternative analogy. Y'all can let me know if this is more accurate:
There's a whole row of elevators. Some slowly head upwards, some downwards, some don't move at all - however, elevators can change speed or direction at any time. More often than not the change is in the downwards direction. Some of the faster-moving upwards elevators have velvet ropes or guards blocking them. It's hard to tell, because you can't really see more than one or two elevators at a time, and the guards are inconsistent, but it seems that to get onto the upward-moving elevators it helps to be straight, white and male. But to get on the really fast moving upwards elevators it's more helpful to be rich, well-educated, socially polished, and connected.
Complicating the picture is the shit cannons. Patrolling the top of the elevators are grinning guys in suits holding super-soakers filled with raw sewage. They blast the climbers at random. A few climbers make it to the top from their own efforts, fortunately avoiding any shit. They believe their success was down to hard work - onlookers say that they merely got lucky. What they really mean is that they weren't unlucky enough to be blasted in the chest with enough shit to send them back down to the bottom. Some people get blasted with a weaker, endurable stream of shit - these people often say that shit sucks but that you just have to deal with it. If you thought that it was grossly unfair that some people had access to the super high speed escalators, keep in mind that these escalators also feature the most brutal and indiscriminate shit cannons. A lot of the shit guards intentionally target women, though a few intentionally leave women alone. Others have other prejudices. It's pretty arbitrary.
Sometimes an entire escalator collapses. Everyone falls to the bottom and has to start again. Except the guys at the top, they're safe.
It's generally agreed that in the past, many more escalators moved upwards. With a few exceptions, a lot of escalators have collapsed or starting moving downwards in recent years. Still, everyone agrees that they're luckier than the guys born far away, who have to fight desperately just to get access to the least desirable escalators.