The problem is that this ideology has deliberately attacked common sense.
Activists very confidentally claim that "science" says that no one can really tell who is a man or a women because it's all about ones inner knowledge of ones gender.
Furthermore, the fact that your own experience and self knowledge doesn't back this up just proves that your inner gender and body are aligned and highlights even more how marginalised and ignored trans people are. They tell you you can't trust your own common sense, you own lived experience on this matter because it itself is corrupted by your experience as a "cis" person.
And that anyone who doesn't accept this, doesn't allow the activists' narrative to overwrite their own knowledge and experience, is a transphobic bigot who is applying the same thought paterns as the racist or the homophobe.
And so they create the conditions where they cannot be criticised because only they have access to "the truth". Anyone disgreeing is simply proving they are uninitiated into the higher truth and therefore unworthy to be taken seriously.
Meanwhile, the very simple and observable fact that people who meet the boring, everyday and obvious definition of "women", the one just based on the gauche and embarassing existence of female bodies, continue to be exploited economically and sexually, and their attempts to highlight this continue to be talked over professionally and politically.