I'm sharing my opinions about language, not being transphobic. What I said is not specific to trans women, I had no reason to think the woman replied to was transgender. If you think my disagreeing with you means I must secretly hate you because you're trans, you're wrong, but I hope the world treats you with more compassion and respect in the future.

“oH i’M oNlY dOiG tHiS wHeN gEnDeR iSn’T rElEvAnT”

That's a distortion of what I said. My claim is not that the non-relevance of gender morally justifies using non-gendered language, I'm not trying to be defensive. It's that a statement using gendered language and a statement not using gendered language is a different expression, the meaning is affected. Think about when singular 'they' was less well accepted, and it was more common in writing to use 'he' as a catch-all term. Yes, readers understood that it was possible the person being referred to was a woman despite the use of the word 'he', but that word still conveyed assumptions about the world. What if that isn't your actual intent? Then you don't use gendered words. That is a legitimate choice.