Yup or be on the receiving end of any number of other gender based slurs which imply that women are stupid, or irrational, or somehow intellectually lacking as a class of people.
It's all fine so long as we're agreeing, we're allowed to have opinions thoughts and feelings then.
Any deviation from the line however and we're making trouble.
Sadly women, often unconsciously (or maybe even consciously?!) do it to other women too, such are the consequences of having grown up in a patriachal society with attitudes and language that promotes and maintains inequality between genders.
Internalised misogyny is a thing that many women struggle with - or in many cases don't even recognise they're carrying around - its so baked into our society.
And derogatory language, against one's own gender, is a very powerful tool of that oppression.
Transwomen are transitioning into a gender that is still seen, and spoken about as 'less than' by so very many people .
They're going to be subject to the same treatment and language as women, only possibly more so as some will see them as having deliberately chosen to 'downgrade' their status, so therefore they are particularly fair game.
I don't agree with everything that
@AuroraSaab says about every aspect of this issue, but she's done commendably well at not rising to the barrage of insults thrown at her.
There are difficult issues raised by this subject, and talking about them doesn't immediately turn you into a frothing hate filled bigoted transphobe.