I admit, I dont know why either. And the hate for her is strong, even among the women I know. Perhaps stronger.
I think the reason many women dislike (or hate) Hillary is because they see her for what she is - a lying, dishonest, enabler of misogynous men, opportunistic, out for her own financial gains, put Americans second behind her own goals, and REALLY not the first woman we would want elected President of the USA. Just as Obama has ruined the chances another Black man will be president for quite some time, Hillary would make such a muck of things NO woman would ever win again.