If that's how you want to define "insult," then I disagree that we shouldn't do it.

You shouldn't attack people for who they are, or anything outside of their control (race, gender, etc)

But for choices they make, that affect other people? These are exactly the things you should judge people for

I don’t follow this logic, at all, and I’m honestly trying to understand it, even if I disagree.

How is attacking someone for what they do an insult?

Is there an ethical line?

If someone kills my family, certainly I am not insulting them for calling them a murder?

Anyone can be judged for the actions they take, that doesn't make it an insult.