Why is Gia getting destroyed for pointing out that male/female/intersex isn't (and shouldn't have to be) men/women? She has never said transwomen aren't women, just not female. That is not radical. It is true. She is getting treated disgustingly.
Because asserting that the human body *is* its sex attributes is gender. There's a difference between saying that a person has XX chromosomes and saying that a body is its chromosomes. Sexing the body *is* a performance of gender. Sex attributes exist as a physical phenomena; how we contextualize that physical phenomena, apply that to human bodies, create norms, taboos and penalties around labels - both personally and within society - *is* gender. Understand, there is a difference between how you contextualize a body and that body. Your understanding only exists in your head, regardless of what combination of sex attributes a body might have.
She's getting shit because in one breath she says that the labels and usage norms around those labels we use to contextualize sex is gender but the labels and usage norms around the binary labeling system she uses to contextualize sex isn't gender.
She's appealing to essentialism. When you hear an anti-trans group assert that because our genes/chromosomes (terms usually mistakenly used interchangeably) make a body male or female, trans people therefore remain the sex they were assigned at birth, they are appealing to a constructed concept of the body. Genotype refers to the genes of a person and many TERFs appeal to this as an essential sexed substance to advance a system of behavioral norms.
Leaving aside the fact that one can go from having XY chromosomes to XX chromosomes, the appeal to genes/chromosomes as a male or female essence that if present, defines a human body in our culture, is an appeal to essentialism. The presence of this a male essence means that the human body in question is itself male and that the (now male) body and society alike must now regard it in a certain way or face certain social consequences.
When you hear an anti-trans group assert that because what is taken to be an acceptably long phallus was discovered at birth, a male sex was established and therefore cannot be changed, they are appealing to a fallaciously constructed concept of phenotype permanence. If a baby is born with a phallus - the phallus being the essence of a man - the infant is said to have been born a man. Like appeals to genotype, this essence is regarded as an ever-enduring locus from which a human body drives linguistic currency in our social system. If an AIS or trans woman has vaginoplasty, a TERF will assert that their sex phenotype has not changed because to admit this change is to admit that a body's sex attributes can change.
In biology, phenotype is expected to change via genetic and non-genetic forces during one's lifetime. This view of phenotype is frowned upon by TERFs. In the Segen's Medical Dictionary, sex reassignment is defined as, "The constellation of surgical and medical therapies intended to physically change a person from one sexual phenotype to another."
She's obtusely appealing to a standard she claims to reject: the gender binary is false; the MAAB/FAAB binary is tots real.