"Personally my response to “le gasp! Some trans women are okay with having penises?!” is “why in the world are you so fixated on a stranger’s bathing suit bits please stay fifty feet away from me if that’s the first thing you think when a trans person’s lived reality differs from your idea of what our experience SHOULD be like.”

This seems to be somewhat of a red herring type argument. Of course, we needn't talk about YOUR suit bits but we can be hypothetical. But genitalia is an indispensable talking point due to one side viewing genitalia as the ultimate criteria in determining sex and gender, particularly these two things are inseparable in the views of said side.