The rule exists because Leftist agitators will use identity categories to balkanize resistance against them, and then disrupt the effort overall.

The fastest way to break up resistance is to make the whites start screaming about jews, the jews start screaming about whites, blacks start screaming at both, the women start screaming about men, the gays start screaming at straights, the employees start screaming at the employers, the poor start screaming at the rich, and so on, and so forth.