If someone says, 'all women should be in the kitchen cooking instead of working' then of course I have the right to challenge them.
If someone says, 'all single mums get a thousand dollars a week in payments' then of course someone should be allowed to point out that's incorrect. Do people really want to live in a bubble of ignorance where none of their mistakes are open to challenge simply because they believe them?
We all make mistakes. I don't expect to be right all the time and I don't expect others to hold their tongues if I completely have the wrong end of the stick.
That's not say people all have to agree, or that its okay to hound people for having a difference of opinion. But opinions are not sacrosant.