Does “* denier” really count as vitriol?

I don’t personally use this language, but for what I think is a different reason: if removing a noun-forming suffix yields a verb which defines the extent of a category, I just think this results in an extraneous lack of specificity (you could instead just describe the subject as performing the action). I also think it’s collectively beneficial to not go out of our way to categorize each other, but I wouldn’t be so quick to apply that to personal situations.

So, I can’t understand taking “climate denier” to be personally offensive or vulgar. If you don’t like your own view, you’re entirely free to just change your mind.