I think civility is something quite necessary in the day-to-day, especially for relationships. Though how 'polite' someone or people are perceived to be, in my experience, is often used as a way to dismiss others - depending on how much that person likes them.
So for example, during the civil rights protests, there were the "pearl clutchers" who thought those protesting for civil rights were being so noisy and rude.
I see this today all the time on social media. If someone is part of your crowd, and they are rude / do something terrible - well no worries. But if you don't like them, well then their lack of civility is a sign of just how wrong and terrible they are.
Case in point, Jan 6th. If lefties eg ANTIFA stormed the Capitol, the GOP would lose it. (As it is, Fox News initially tried to claim there were ANTIFA agitators) Seriously can you imagine if BLM protestors knocked over things in the Capitol and posed shirtless there?
But ofc it's not just people on the right. Plenty of people on the left will hear a rude comment from a vegan and go ah HA, see?! ALL VEGANS ARE RUDE.
So I guess, to conclude, it's human nature to look for reasons to condemn or forgive those groups of people we dislike or like, respectively. Civility is one metric we use to do that. How much we care for civility in others depends on how we feel about them.
Sorry those people were rude to you. I'm (overly) sensitive, I sincerely wish rude people would disappear. They just make a tough world that much worse...I honestly think it's everyday rudeness that ruins most people's days (and everyday kindnesses that mean so much). For good or bad, it's the little things that add up.