source: https://www.reddit.com/r/slatestarcodex/comments/11mddex/give_up_seventy_percent_of_the_way_through_the/jbhjh3j/
But politeness is just signaling!" So is impoliteness; it signals contempt, hostility, malicious disregard.
If you don't actually feel contempt, why signal it? It's not like you can not signal. Mammals were signaling with their voices long before they developed syntax.
Yes, in order to be polite in an ongoing way, you have to keep track of changes in what other people think is polite. Yes, that requires effort. Surprise: if you want to credibly signal not-total-contempt for others, you have to practice it. That's the trick, see: other people get to find out how much you care about what they think!
Context: changing preferred terms and terminology for people and groups.
See Also
"My mom would say there's a bag of apples on the couther in the kitchen and I'd say okay I'll have a pie ready for dinner and my husband would say "Wasn't she just offering an apple?"
(from Tropes and Misinformation)