As I said, it's rude to THEM. My point is that you are deciding that you are not rude, when you shouldn't be the judge in this case.
If someone is rude to you in your eyes and based on your standards, how you react is still on you and is your responsibility. You can still be respectful to rude to people.
Respect is a two way street.
By abandoning any pretence of objective analysis you're reducing rudeness to a meaningless concept.