The problem you're having is that your looking for a logical answer without considering the mindset of the other side.

They aren’t trying to build a reason based/lawful way to defend themselves.

They are using bad faith and/or weaponised ignorance to be cruel dicks, that's the point.

They can then build on top of this to be even greater dicks to a larger variety of people.

There are potentially other motivations in the bigger picture, but at this level it's just "how can i weaponise my truly astonishing levels of crippling insecurity to hurt the 'other'" because that's how they pretend they have control/power enough to enjoy life.

They're the self-appointed Gender HOA, giving out citations because they have nothing else in their life.