Ah, the loaded question argument.
Everyone should be protected, but how can people be protected when reassigning their sex, when its impossible to reassign sex?
Who are we protecting and what are they doing?
Are we protecting men to perform drag at work?
Use a woman's name?
Hide their sex on documents?
Pressure companies to remove SSE because they need to balance rights of these men with women.
Stop people laughing when a man uses 'woman' voice?
Stop people from saying they are a man?
When people claim its about access to work, they are only talking about half the story because its not only about recruitment, its about how other people are expected to relate to them.
Its about MrJohn Smith being able to change his name to Miss Jessica Smith, even when they are a school teacher.