You can however tell him you disagree. For the sake of children that are listening if nothing else. The rules of this are ridiculous anyway.

Why is there selected group of people and opinions who can run their mouths and everyone else must shut up else they destroyed the event?

This is nice example how something completely different: social hierarchy where it is super importsnt to keep illusion that some people are right.

> Telling your climate change denying uncle he's an idiot won't change his mind

Usually it does change his mind if he respects you enough. It wont work on a stranger but it is very effective on long term friends.

No, that’s a very naive view. There are many people I respect who will have different views from my own and the only thing them calling me an idiot will do is lessen said respect.