In my opinion
Because whilst they may try to get us to use different words for those things that is about all they can do.
They can take away the means to describe ourselves. They can stop us being anywhere in a space that we can guarantee is 100% female female!
But they can not and will not and will never be able to be pregnant have periods or go through the menopause. And as much as they would like to, they can't stop us experiencing those things. So the will to fight for those isn't there, as much! especially as they are the three main "problems" with being female!
And the transmen who still have to go through those things, in the main probably don't want to talk about them that much because they don't want to actually have to accept them as part of their body.So they are not going to be shouting out loud and proud about those generally!