Yes saying that you’re exclusively attracted to cis women is an easy short hand.
I think OurToothbrush is frustrated with the erasure of transwomen that you fail to identify as trans.
I think when you said:
I had never met a transfem whose body I found attractive.
You don’t actually know if you’ve ever found a trans-woman attractive because you don’t know the birth details of every women you’ve ever found attractive. Some of them could be trans.
It’s not something I was particularly cognizant of either before seeing OurToothbrush’s reaction.
I think I would have trouble getting it up for a blow job from a smoking hot women after I learned she had a penis. I’m willing to concede that that is technically transphobic. I don’t think it changes the fact that I am an ally of the trans rights movement.
Just say you’re a cis-het male ally and I think everyone will know what you mean. It’s too bad this has been sick an ugly experience, it’s still a hell of a lot easier than gender dysphoria.