I think it’s a combination of an extremely very poor understanding of human biology, magical thinking, and others in their echo chambers reinforcing their crazy transhumanist fantasies.
A lot of troons seem to source their medical knowledge entirely from other redditors and twitter users; anyone who posts anything remotely common sense, evidence based or realistic is downvoted, banned or blocked.
Because we can transplant some organs, this makes any organ in the human body “plug and play”. I don’t think a lot of people understand that a kidney transplant isn’t just removing a knackered kidney and slapping in a new one like it’s a car battery and job’s done.
Also, anything involving the female reproductive system is poorly understood by the public at large and troons especially. They don’t understand the intricate relationships between hormone levels which trigger the stages of the menstrual cycle, or the various ways male and female bodies differ due to the presence or lack of a whole extra set of internal organs which may or may not end up growing an entire other person.
Their magical thinking is part of their entitlement. Who cares that nature has designed a complex and delicate system over millions of years of evolution in order to facilitate sexual reproduction? If they *want* a vagina/ penis/ uterus they’ll be able to have one, God damn it!