For the same reason that it's "bad" in hockey or football when the visiting team does it, but it's "good" when the home team does it. ;-)

Until the audience realizes that the game is rigged, and that both teams work for the same corporate management, the old partisan silliness and blind prejudice and hatred will just go on, and on, and on, and on....which is exactly the way head office wants it. Without you partisan dummies constantly attacking each other, you might decide to attack the corporate bosses instead, and that would bring the system down.