"Gay men and lesbians weren't demanding the use of the opposite sex's spaces, sports, awards, etc. They just wanted the same rights as everyone else. There is no comparison."
This should be said over and over.
The sub group of male people who are demanding that they have their philosophical belief be affirmed, that they are somehow a female person, are asking for extra rights over every one else.
It is also very important to remember that the word 'discrimination' is not inherently wrong. That under the EA2010 legitimate discrimination is allowed where people of the male sex can be excluded, even with a GRC, from some situations that an organisation has claimed an exception for under the Act.
Discrimination that was negative towards homosexual and bisexual people was always wrong and considered 'illegimate' in comparison to the legitimate comparison that allows male people to be excluded based on their sex.
I really think that the rejection of the false comparison should be repeated constantly until people stop making that comparison.