I agree. The advice is sound. I wasn't taking issue with the advice, only with the premise that society as a whole has adopted the standard "You can be an ass

I agree. The advice is sound. I wasn't taking issue with the advice, only with the premise that society as a whole has adopted the standard "You can be an asshole, as long as you're right." Maybe, phrasing it more positively, I would add to the advice. (1) Try not to be an asshole, as you're winning an argument. (2) Don't try to win an argument by demonstrating that your opponent is an asshole. Some people tend to foget about (1). Others tend to forget about (2).