The concept of passing is the problem. To ‘pass’ is to successfully deceive people about your sex.
Just because you’re justifying that deception on the basis that you really strongly identify as the oppositive sex, it is inherently about deception.
There are situations where someone’s
sex just doesn’t matter at all - and the idea of deception just doesn’t matter. Whether my bus driver is male or female is of absolutely no consequence to me as a passenger. Whether the new hire in the accounts department is male or female
matters not one jot to whether they can do their job.
In those kind of cases, their desire to ‘pass’ doesn’t matter because the people
around them don’t need to know what sex they are.
But there are situations where it does matter and it’s not ok to deceive anyone. If the company wants you to travel and expects room sharing, then the sex if your colleague is likely to matter. Same when it comes to sharing single-sex spaces.
It absolutely and fundamentally matters if you want to pursue a romantic and/or sexual relationship with that person. The idea that one partner should be allowed to deceive the other about their sex so that they will have sex with them is abhorrent. And indefensible.
Overall, the whole concept (and goal) of passing is a problem.