This is particularly ridiculous. Biological essentialism because basic biology is intrinsic to sex, conception (even if artificial it involves an egg from a woman and a sperm from a man) and birth. If this is transphobic then life itself is transphobic.
Therein lies the problem.
If your whole world view involves denying material reality, like King Canute denying the tides*, then you're bound to struggle psychologically when your world view collides with the facts - and this sort of psychological struggle often expresses itself as outbursts of anger and raging about the transphobia of people pointing out to you that unfortunately the real world is not as you would like it to be.
(*I know King Canute was actually making a point about the limitations of the power of kings to his advisors.)