It's all language, isn't it?
We're using the long standing definition of women. E.g. adult female humans.
Transwomen are males who wish to appear as feminine/female-like. Humans cannot change sex.
Transwomen literally cannot be women.
In order to believe that transwomen are women (as opposed to a fictional metaphor for kindness/acceptance) you have to either:
- Believe that humans can change biological sex - an extraordinary claim that requires evidence. And you'll need to explain at what point this sex change occurs e.g. at first declaration/hair and clothing change/GRC/ hormones/surgery etc. And how the sex change could be independently verified e.g. DNA swab.
Or
- You need to redefine the word woman to no longer mean adult female human. This sounds easier but the problem is that if you include adult male humans in the definition then it becomes absolutely meaningless, any and all humans are women. Alternative criteria like "feeling feminine" might include both some females and some males, but it also excludes many females, and I'm not just talking about transmen, non binary females or even butch lesbians. Loads of regular women don't identify with the gender stereotypes/roles/expectations associated with our sex, not least because they were used to control women and prevent us having power in society
Women who don't have stereotypically feminine interests/hairstyles/hobbies/careers/clothing are not somehow sub-women or part-men. We are female, and are just as affected by, female bodies, sexism and women's rights issues as more feminine women.
Defining womanhood on regressive gender stereotypes isn't enlightened, liberal or progressive. It doesn't make people more free.
Yes, we can't change our biology, and it will always have consequences for our lives, especially healthcare. But it doesn't have to limit our careers/hobbies/personality.