It really isn't very important, though. We queer people use the term cisgender because we need to. We need to talk about ourselves and make distinctions so we can understand one another.
Just two days ago, I was welcoming a new editor to Prism & Pen (a queer publication) in our Slack workgroup. I suggested a general round of introductions and started off describing myself as a "62 year old, cisgender gay man."
The alternative would have been to say "a 62 year old gay man who is not transgender." Awkward at best. And imprecise. The world is not strictly divided into trans and not trans. There are nuances. So, when I called myself cisgender, everyone knew what I meant without the need for further explanation.
It's also very awkward to write publicly about queer issues without using "cisgender."
Not using that word makes communication quite difficult. Not using it changes clear writing into convoluted, sometimes hazy or imprecise writing.
It's only very recently that anyone thought or claimed that cisgender has negative connotations, and it's critical to understand that the people who first made that claim are fiercely opposed to the public existence and acceptance of transgender people.
The folks who started the campaign against the use of "cisgender" did so because the despise "transgender."
There simply is zero reason to buy into negativity about a neutral, useful, descriptive word did many of us queer people claim as our own identity.
I've never once heard a queer person use "cisgender" as a slur, and I've been active in LGBTQ advocacy since 1990. We do no-one any favors by buying into the falsehood that "cisgender" has negative connotations.
It does not.