What I said was not to mean that "not having a penis" is a prerequisite to enter a toilet. This is so complex to put in simple terms, because what TERFs say is an inconsistent cocktail of hateful ideas, that contradict themselves. But no one is examining genitals to enter any toilet. They just appeal to plain old cisgenderism, "people who look like men must have dicks and people who look like women mustn't, because these are the two natural categories and I want to be able to put anyone neatly into them, except some freaky accidents of birth". Their actual problem is that legitimization of transgender individuals threatens the very core of this cisgenderist ideal, which only lead to the corollary that trans people are not natural and should not exist. I intended to write sth else entirely but this is the cornerstone of the whole discussion, that cisgenderism is the substrate and breeding ground of transphobia and perhaps we should start discussing in these terms instead.