*I also have a trans child and personally I find it exhausting, every time you try and open a conversation up people, usually subtley, but other times not so subtley, try and find a reason, something that you did, so they can pat themselves on the back because their parenting is superior, and yours is so crap.
I find it hilarious that people say "gender is a social construct" and then go on to list reasons why they aren't enforcing those roles (I have short hair, don't wear makeup, fix stuff etc) which is, in fact, enforcing those roles in itself.*
I can see why it can feel like you're being judged esp as the context has become so toxic that there really is no discussion anymore. My reading of it (from outside, I have no-one in my family who is trans) is that people are really not trying to blame the parents but rather trying to unearth the conditions which might lead people to feel that they need to feel there is a link between what their bodies look like and their identity. Some of the influence will come through parents but it will also (in much larger spades) come from schools, messages in advertising, stories in books etc. Parents will pass on stereotyped messages which they are enacting without awareness and some will be more or less aware of what they have internalised. But this is not to blame parents. I think the questioning of "what went wrong" is not a question of "what did you do wrong". At least that's how I mean things. As a culture I think we are failing our children massively at the moment. It would be ridiculous to put the blame for that at the feet of parents of trans people and to do so would be a barrier to progress. But not looking at the conditions which have caused such distress to so many people would also be a barrier to progress.
I don't think that pointing out that many women do not fit old-fashioned gendered views is reinforcing them - rather it is deconstructing them as it points out that for many people there is no such thing as dresses/ thinks "like a woman". How do you think that saying "I don't fit the old-fashioned stereotype, how about we move on from that?" is reinforcing the stereotype?