Getting angry when a stranger makes a statement that you disagree with is not a normal social reaction, or at least it wasn't until recently. The possibility of error is just one reason that it shouldn't be.
Yes it is. Heck if you look in the history books there are plenty of examples of people not just being criticized but actually being murdered over the statements they make. Which statements draw social ire may change over time, but you can't seriously be suggesting that until recently nobody got offended ever.