Some, not all, transwomen feel dehumanised and disrespected when they are denied the status of being a women. This shouldn’t be minimised or denied.
No one is minimising the impossible. They certainly aren't denying it.
Sex is not gender and you can't change sex.
No matter how much any of us might be sympathetic to the concept. In an ideal world, I'd wave a magic wand and it would be possible.
But it's not, and we can't.
So it's something that people in this situation need to deal with instead of expecting the world to dance around pretending to the contrary. That's where the harm is - in a failure to address reality and the repeated denial of there being an issue.
We don't say "oh well we should tolerate drug or alcohol abuse", because x is in denial they have a problem. They still have to take responsibility for that. They might have lots of other problems that have caused that to occur which we can be sympathetic with due to circumstances. But we shouldnt be sympathetic about the unacceptable behaviour.
Likewise we shouldnt affirm an anorexic in denial.
Nor someone in denial over being pregnant. Or any other issue.
We are sympathetic to the circumstances of people but not to the disordered behaviour and unreasonable demands that go against reality.