There are even more biological differences between Females and Males than just hormones.
Science isn’t transphobic. It’s just, well… science. Knowing that biology exists isn’t transphobic.
Yelling abuse at trans people in the street is transphobic. Discrimintaing against somebody (work rights, housing etc) purely becuase they are trans is transphobic. Attacking, raping and killing trans people just because they are trans is transphobic.
I think it would be really beneficial to transfolk to get past this notion that mentioning biology is somehow transphobic. I’m male. I’m trans. No big deal.