I think there's a combination of many things which makes it nearly impossible for them to win. They're mostly seen as physical threats compared to other genders stereotypically seen as weaker than men and being a female are probably more susceptible to mood swings that may be seen as problematic by some of their tribe members. I think a lot of it also has to do with the unwillingness of the male to be intimately connected with them which makes it a hard sell during a tribal council and they are probably the first to go if an all-female alliance gets blindsided
