I don't say this from a political point of view (though it probably applies there also). I say it from a day to day point of view, with fuck face people. If a fuck face thinks he can fuck with you, kick your ass etc, they'll try to fuck with you and get very irate around you - potentially leading to violence. Violence that civilized society doesn't want, that law enforcement don't want etc. If a fuck face is afraid of you, you could insult his mother to his face and they'll still be extremely reluctant to engage violently with you. i.e. crap rolls downhill. Fear is the greatest prevention against that.