He is warning Andrew Neil that doctors simply wouldn't be performing these surgeries or prescribing the medications, without it being the best thing for the child. And is under the impression that the input of parents, doctors, psychologists, etc, can't all be wrong.
Possibly off-topic, but I find this quite a common attitude to all sorts of things doctors do, not just gender medicine. Years ago I once had a medical problem that was misdiagnosed, followed by a hospital doctor proposing drastically wrong treatment (luckily I ended up seeing a consultant before this could happen). I remember telling a friend about it, and she basically refused to believe me, saying I must have misunderstood the doctor. This despite the fact that both she and I are intelligent, educated women.
Yet if you decide to listen to other people's experiences, or even read newspaper reports, then you'll find that doctors get things dramatically wrong all the time, and then the hospital covers up for them. This is a fairly recent example, but there are a ton of others:
https://www.bbc.co.uk/news/uk-scotland-65904293
So it's not entirely surprising that people refuse to believe that doctors are giving young people dangerous drugs or performing harmful surgeries on them. They simply think that that's not the way doctors behave.