Where I work quite a few people complain about others like calling them stupid and other negative comments.

I know most people say they walk away and don't respond or ignore.

I think it is best to reply back so they realize that everybody is human and that what they said was wrong. I do know some people think the opposite and aim it towards you, say that you are wrong or get angry. That's when I would walk away. Which would it be wrong to ask them why they think it's fine to call others stupid.

I also was thinking that maybe say things like "Yes, others can do stupid things though we all have those moments." Or if someone is implying by saying something sarcastic, saying something like "Thanks, for reminding how hurtful insults can be" or telling them that I disagree.

What would you say?