The problem with mob rule is that it is not mob rule for very long, so it is difficult to tell if it is impolite or not. Mob rule does not last very long, because it is promptly hijacked by opportunistic individuals who use the general state of anarchy to propel themselves to the leadership position and impose their own autocratic rule. And that is usually quite nasty.
"Revolution usually eats its own children" - which is to say that revolutionary movements are quickly hijacked by opportunistic autocrats who finish off the revolutionaries and idealists who started the uprising. The Reign of Terror, Stalin, Moscow trial, the Night of Long Knives - the list is long.
Wojtek