Calling people names, or otherwise disparaging them, isn't going to make people reevaluate their views. All it's going to do is change their opinion of you.
If you don't have a counterargument, it's ok to say nothing. If you do have an argument, then there's no reason to fly into a snit over somebody's statement.
It's a big world, with lots of viewpoints. Throwing a tantrum whenever someone's understanding differs from yours is not very productive.