I’ll explain what the issue is, for the hard of thinking.
The Supreme Court made it clear that single sex toilets were for use only by people of that biological sex. A toilet allocated by the National Trust to men should not be used by women who claim to be men. Doing so breaks the law.
As no man menstruates, nobody in a male toilet has any need for a tampon. So, by deliberately putting tampons in there, the National Trust is making a statement that 1) they expect women to use it, despite it being unlawful; 2) that they actively and knowingly encourage this; and most importantly 3) that if women can do this in the venue then men can feel equally entitled to pop into the ladies.
Now, nobody can make anybody else care about these things. But once you’ve been flashed at in a female toilet by a man pretending to be a woman, as I have, or seen graffiti which says ‘a trans women spunked here’, as I have, you may engage your brains and hopefully consider that we’ve kept men and women separate in open plan public toilets for decades for a reason. I’ll provide that reason in a moment.
Your home toilet does not count. You know the people using it. The plane toilet does not count. It’s a lockable self-contained space where nobody can flash you and run off, unless they open an emergency exit. Your unisex work toilet does not count if all of the toilets are single unisex cubicles which are enclosed top and bottom, usually designed with doors opening into a long corridor where anyone can see who comes and goes. Creepy men can’t hang around there. They can only wait for a person to exit, then enter.
The toilets that count are ones where you turn into an architecturally-designed blind privacy corner, designed to shield people from the eyes of anyone hanging around the entrance, because that’s where finding a man in a dress can be a shock to a lone woman. It’s the ones in rooms where each stall has open tops and bottoms, where man can look under and over, and masturbate to the sound of you urinating. If you don’t think this happens, you need to get online and start reading. You’re in for a treat. It’s the ones where men can stand leaning against the wall, watching women apply makeup, even if it’s clear that their staring is uncomfortable - that’s part of the fun for these creeps. Again, if you don’t think this happens, you’ve been protected. How great for you, but you don’t get to give consent for everyone else.