Is it offensive to say "straight" or "neurotypical"?

[MerlinsLostMarbles]

I've been trying to understand why the gender critical movement are saying "cis" is offensive and still not quite getting it since it just means "not trans" (cis and trans are prefixes with opposite meanings).

From what I can gather the argument given by the gender critical movement is that the "default" is not-trans, therefore there shouldn't need to be a word for the "default", just as we don't have a specific word for someone who doesn't collect stamps (an example I've seen given).

But we have "straight" and "heterosexual" to refer to people who aren't homo/bi-sexual, we also have "neurotypical" to refer to people with typical neurological development or functioning. You could say these are also "defaults".

So why is "cisgender" an apparent "offensive slur" when straight and neurotypical aren't?

'Cis' effectively means 'adheres to gender stereotypes along with most other women'.
It's entire meaning is deeply sexist and rooted in conservative and outdated ideas of what women are.
We'll hear trans activists claim it doesn't mean that but the moment you ask them to clarify any of their definitions and pin it to anything tangible, even something as simple as what women are, it's all 'Mumble mumble. Bigot! Dogwhistle! No debate!'
So no, I will never accept a label as misogynistic as cis.