The reason women hate men is because they have a genetic predisposition to discriminate against men. The gene called TRP2 is present in both males and females and it activates upon sex detection of a male. In other words, whenever humans detect a female this gene does nothing. However, when a woman detects a male this gene triggers a predisposition to discriminate. This is very useful when selecting a mate that will be able to provide for offspring, however it is not very useful when aggravated by a political ideology such as feminism. Feminism turns a predisposition to discriminate into hatred by scapegoating all men as the wellspring of all female unhappiness. (Men, however, have done far more good for women than bad but this rarely factors in to female thinking.)
Women get away with their hatred of men because of several reason. First is that they control reproduction. If the human race wants to survive it has to keep women happy and that means putting up with their misandry.
The second is that TRP2 in men triggers competition and domination. Men will naturally allow other men to be scapegoated as a way of eliminating competition for reproduction. We are not conscious of this however.
What keeps it all in line is cognitive dissonance. This is nature's little moral compass. It is anxiety we feel when we have ideas which conflict with our actions. Whenever humans do something that might be counter to our evolutionary programming cognitive dissonance kicks in.
For instance, the visceral feeling many people get when they think about homosexuality is cognitive dissonance and it tends to lead to homophobia or even hatred of homosexuality.
Women, however, feel no cognitive dissonance when they discriminate nor when they hate men. What has kept female hatred of men in check for thousands of years is that women needed men to do the hard work that was required to survive. Today, it's easy to survive in society and men are considered "optional".
Female hatred of men as expressed in feminism will continue to grow and strip away male rights and freedoms until a critical mass of men realize what is happening to them and learn how to combat this hatred.
When this happens women will find out what true equality is. They will likely become just as disposable as men have been for thousands of years and the word "chivalry" will be as ugly as any racial epithet. more and more women today are into their own sex nowadays, and that certainly would explain it.