I can tell you're being funny but I'm not exactly sure what you're saying. Taking your comment at face value (sorry about that), "carnist" was not intended as a slur, and certainly is not defined as one. Carnists are people with the (typically unconscious, unexamined) belief that sometimes it is acceptable or even good to be needlessly cruel and violent to animals. The word contrasts with vegans, who believe needless cruelty and violence are never acceptable or good. It was coined by Melanie Joy in their 2009 book, Why We Love Dogs, Eat Pigs, and Wear Cows: An Introduction to Carnism.

The person you’re replying to is the kind of person that makes rednecks proud to eat meat. Personally, I don’t care if someone thinks I’m doing it to virtue signal; I’m going to eat meat alternatives when they taste as good as meat, and Impossible meat does taste as good as meat. Reducing our overall meat consumption as a society is a good thing.