So you all think it's normal if a lecturer/trainer invites students/trainees into their home and discussed their genitals and the students/trainees just need to "toughen up"?
I think if I were making a point about something to do with, say, what I thought about wheelchair users' rights, and someone said "but you have working legs, right?" that would be a valid thing to say. Similarly if I were claiming to be non-binary not as a state of mind in a sexed body but as an actual statement that body sex does not exist for me and someone said "But you were born with a vulva not a penis or a third thing, right?" that would also be a valid thing to say given the context of the conversation.
It can't be ok to have someone able to demand a group acquiesce to a claim that everyone knows is false simply because it's too rude/indelicate/triggering to say the truth that exposes the falsehood.
So if someone pushes a false argument to a place where the only way to counter it is to say something that is true but generally considered impolite to mention, they will unfortunately sometimes find people who consider being rude is better than condoning a lie (or more charitably, a misapprehension), especially if they consider this falsehood to be harmful to people other than just the liar.
If a truth is too dreadful (or simply too socially unacceptable) to say, that unsayability becomes a cover for people with bad intentions. As the many women who put up with boundary-crossing behaviour from men because they feel pointing it out will be seen as "making an unwarranted fuss over nothing" can attest.
As an aside, and related to points on a recent thread, I find it very odd that the current shibboleths of so-called (but actually not) progressive politics include both trans identities "Shhhh shhhh must never mention the genitals, what sort of awful awful person wants to know about genitals anyway???!!!" and Sex Work is Work "Being a person who wants to pay to
use or look at other people's genitals is totally ok and only prudes have a problem with it!!!!"