This sums up a lot of the core problem around "trans" IMO.
Gender reassignment is officially a legal status and protected from discrimination in law, and I understand that. But more generally, it's perfectly normal and understandable to dislike or distrust people who pretend to be something they're not, or who expect others to pander to their beliefs.
If you employ a religious person you don't expect them to try to shove their beliefs on everyone else and compel everyone else to pretend they believe too. And if they did do that it would be OK to discriminate against then (e.g. not employ them) on the grounds of them being difficult and unreasonable. That wouldn't be religion-phobic, just demanding-controlling-twat-phobic.
If you were holding interviews and someone came along and explained that they're not disabled but like to "identify" as disabled and demand all the associated provisions, you'd probably think they were a nightmare and had a loose grip on reality and therefore might not be the greatest employee.
But with gender the two have become very wrongly intertwined. Pretending to be something you're not and imposing it on others is in itself the protected characteristic. So it's very hard for people like employers to separate the characteristic from PITA behaviour.
I know there are trans-identifying people who do respect others' right not to play along and I appreciate that - but they're probably being disadvantaged by the demanding ones too.