I avoid buying from people that are consistently rude. Once in a while isn’t a big deal.
We all have bad days.
I have a friend who owns a hobby shop. He is a great guy, looks out for his regular customers, tries to be welcoming and helpful for new people, sends customers to other local stores if he knows they have something in stock that he doesn’t. Sometimes he is having a bad day and says something inconsiderate. He has lost customers over that and he is aware of it and he regrets it for the lost relationships as well as the income.
He used to employ this guy who didn’t like a popular product line. This employee would bash the game in front of customers. He found he had a lot of stock he could no longer move as those people went elsewhere.
People will react to the things you say or write. You have to be careful or it will cost you. But retailers and manufacturers are still just people, too.