They have come to a conclusion first and then reach for anything and everything to "prove" it.
It's simple. If you were born with a penis you are male and if you were born with a vagina you are female. Case closed. Any attempt to refute this is laughable.
I'm not saying it's not possible for a male to prefer things and activities that generally females prefer. What I'm saying is that certain constraints imposed by society imply that the male MUST in fact be female if they have such preferences, and the person erroneously buys into this myth and mistakenly believes he, indeed, must really be female.
Now, that's logic and reason, something most of the "expert" sources you continually cite sorely lack.