I assume it's a bit like how a few straight people used to object to the term 'straight', generally complaining that they were just 'normal' people (haven't seen this in years, but it was big in the nineties and early noughties from the more over-sensitive corners of the right wing).

Though arguably even more absurd; 'cisgender' is the rough equivalent to the rather dry technical term 'heterosexual', and I've never heard of anyone objecting to _that_. It's not even slang!

"Cisgender" is obviously not a slur, come on, but this is Saint Car we're talking about; one shouldn't necessarily expect things to make sense.

(One wonders how he thinks people _should_ describe non-trans people).