"Its no different than the word marriage."

It's very different. Marriage is an institution, or a social construct, as the kids like to say. Women are people.

Gay marriage doesn't infringe on anybody else's marriage. If we all decided tomorrow that animals can get married, everybody else would remain exactly as married as they were before. As long as you don't downgrade the legal status and rights of married people, it makes no practical difference. So objections to the change were based purely on what people thought the man in the sky might think.

But women's rights are based on practical, physical realities related to being female. If you change the definition of "woman" to include men, you necessarily infringe on the rights and safety of women.

And yes, I've said many times that trans women are women was an insane and self-sabotaging hill to die on. A legal compromise that allowed trans women to use certain women's spaces had already been found. It was the trans lobby that spent the last years demolishing all those safeguards, ignoring the negative consequences they created.

So now, sadly but unsurprisingly, people are less willing to compromise.