Pestilence

It's deep in our subconscious--the whole Christian version of things. Maleness is ultimately righteous, even though susceptible to normal human weakness and sin. Femaleness is devious and corrupt (Eve in the garden). So we keep replaying this myth again and again, and the wrong people get rewarded and others suffer

The worst thing is, it rings true. If someone points out that a random woman is weak, we instinctively feel it to be true -- without having to know the facts.