It's extreme sexism, and the fact that it's accepted in today's society is an utter, sad travesty. If a man openly expressed, let alone preached the opinion that all women are [insert female stereotype here. Unintelligent? Slutty? You get the point], he'd be hunted down and would probably face legal trouble. Which is good, because it's a dumb prejudice and something we as a society should strive away from allowing to spread.
But if a woman speaks on equal levels about all men, hell, worst case scenario she's a little unpopular. What in the world is up with that?! How are real gender equalists (I prefer not using the term feminist as feminism nowadays is more about oppression than equality) supposed to make any progress when crap like this is still accepted in society? It's counter-productive, sexistic madness, and that's all it is.