It's a deep refusal to accept that trans people should be taken at face value, or that their own words have any merit, when posters endlessly assert to know better about the trans community, and that includes trans people who can only speak for themselves.
Sounds like you want to have your cake and eat it too @crispbutty. We can either take everything trans people say about themselves at face value, or we can evaluate their claims to see if they have any merit. It's not possible to do both. One cancels out the other. To take somebody at face value means we accept whatever they say as true without thinking about it even a little.
Do you not see how unreasonable it is for a group of people who are making the most astonishing claims, to to demand that we take these claims at face value? The only other group of people that I can think of who demand such special privileges are religious groups, especially those who want to see creationism taught in classrooms.