Comments by "Johanna S. L. Brushane" (@johannas.l.brushane2518) on "5 Psychological Tricks Bullies Use (And How To Stop Them)" video.

@orelas167 Indeed, and they also pointed out that it's for when it's a person you may have to do with, if you for some reason are less inclined to walk away to simply ignore and walk away. And telling someone that they have poor manners isn't really saying anything about whether it personally annoys you. That is of course that the bully in question doesn't have straight malicious intent but rather throws a raw jargon in some attempt of trying to look cool, tough etc. Having a co worker or a member of a sportsteam pointing out poor manners may sting somewhat, given it's a context where they don't want to be seen as unprofessional.
4
It depends on the context. And they did not phrase it as you quoted it. They phrased it in a way to pinch the bully's poor manners, lack of social skills not stating anything whatsoever about how you really feel about the insult. If it's a bully in a workplace, a sportsteam or similar it could well work when essentially being told that their behaviour is disruptive, especially if they are doing it because they think it's a cool jargon (they also said it was for when in a situation where you had to deal with the person).
1