If you're a feminist, but trans-exclusionary, you qualify for the "radical" part.
History and relevant link: https://en.m.wikipedia.org/wiki/Sex_verification_in_sports#:....
that is a non-sequitur. the conclusion doesnt follow from the premises.
The problem is that many women (who are not trans) have a Y chromosome. They are either XXY (Klinefelter), or XY (Swyer), XY mosaicism, or any of the other intersex conditions.
Are those people not women? They may have fallopian tubes, a vagina, and a uterus, but also a Y chromosome.
why? Do feminists already "exclude" cis-men?
"Men can't be feminists" is a hotly debated talking point in the feminist community.
I suppose it's also possible that some people who are trans exclusionary would take offense at being called (radical) feminists...
But calling someone who is anti abortion "pro life" or even "anti choice" is not an insult, even if I find their position misguided and monstrous.
If I believe all billionaires are a policy mistake, am I insulting Elon Musk if I call him a billionaire?
It is if it's said as one. Benign terms can become slurs when used in the right context with a particular tone.
Retarded accurately describes the mental development of certain individuals. Retarded was not always a slur. I'm sure you would agree it is used as one now. Not sure why you think TERF should be some sort of special exception.
On the other hand, TERF doesn't imply any particular disability, just a belief that those it is used to refer typically do hold. If TERF started being used as a generic insult for someone who makes a mistake ("you can't put that there, you TERF"), like "retard" did, then I would agree that it has become a slur - but this is not the case.
Have fun though.