Hey @kyriacos, how's it going? I think you're a little mistaken there... Sterlin didn't advise people to be rhetorical - That was a description, not a prescription, and you can see that when you read the sentence in context.
Both online and offline, we often rely on rhetoric lined with insults and hate instead of peaceful dialogue. Employing this language is not persuasive, but I am not suggesting that we should be perfect or that we cannot react defensively when provoked.
Besides, "rhetoric" in the broadest sense doesn't necessarily mean being deceitful. One definition of "rhetoric" is: "the art of effective or persuasive speaking or writing".
I hope that helps clarify things. Have a good one