If you think that you have a right to behave how you wish, be anyone's guest. Just don't complain when you don't get your expected result. As that's how etiquette works. Its enforced through social punishment, and often without saying a word.
There are good reasons for most basic rules of etiquette, especially in public conversation. Protecting those reasons is a strong incentive to enforce the etiquette.
You're over-simplifying what I said when you state that people don't have a right not to see emotion. This is specifically in regard to politics, and the greater consequences of spontaneous political conversations including but also beyond being uncomfortable. What I was implying is that said emotion, in regard to politics, too often frequently leads to group tumult. Which is one aspect of why the etiquette exists.
I'm sure you can find people who will go out of there way to argue with you. But to expect random common people in their few precious leisure hours to not avoid you is asking too much, should your preferred topic of conversation be politics.
