No ‘a man can never be a woman’ is a fact and mainstream view. Disliking your sex isn't an innate characteristic and you have no right to force others to believe your illusion or participate in your gender performance.
More to the point you just claimed discussion of these matters wasn’t ever suppressed and then attempted to suppress discussion of them by claiming this was bigoted.
People with gender dysphoria exist. THey are not marginalised: they have the same rights as every other person has. It is not bigotry to not participate in their gender performance, because gender performance is not an innate characteristic, as already mentioned to you in the comment you're replying to.