some people appear to hold that only viewpoints which they agree with have a right to be heard.

Yes. I think some people have difficulty with the situation of differening opinions all based on incomplete evidence.

Faith, belief without evidence, is an easy option for debate, and accusations of delusion, because most can agree that there is no evidence. Debating the pros and cons of the views of, say, Adam Smith and Karl Marx, often involves taking stances that can look like 'belief with incomplete evidence'. Delusions of certainty maybe.