You seem to want to believe it's all sexism. Accusations of sexism are used as an office political tactic far more often than actual occurrences. Civil rights activists? Hardly. Using PC sensitivity training violation accusations to back stab people? Absolutely.
I never spoke about myself but I've heard professional career woman say this and they're not bitches either.
Did you actually work with these women, or are you reporting hearsay? Has it happened to you, or are you going by anecdote? I've heard professional career women say this and who also claimed they weren't bitches. But everyone who actually worked with them disagreed.
It's happened to me but more in the context of discussing political issues where I'm told to go do some dishes and be in the kitchen where women belong. It's odd that someone would say that to me considering I want to be a stay at home mother. I've hardly met a man that disagreed with my choice of 'career'. As for my friends, I have no reason to believe they lie to me. I don't doubt there are women like Omarosa in the workplace but that's not every woman. There are things a man can get away with that a woman can't and not be called a bitch.