You have completely missed the point I'm making here.

I very specifically said that if "you're trans" is the only reason for rejection, then that is transphobic. And it is.

If you have quantifiable reasons, then that is fine. If you can identify why a person being trans is an issue for you, in a way that isn't just "ew trans icky", then you have a valid reason.

The point, as always, is that "you're trans" - by itself - is not a valid justification.