You don't understand. If they ban the bad people then there will be nothing but good people left.

"The mind should develop a blind spot whenever a dangerous thought presented itself. The process should be automatic, instinctive. Crimestop, they called it in Newspeak. . . . He set to work to exercise himself in crimestop. He presented himself with propositions—'the Party says the Earth is flat', 'the Party says that ice is heavier than water'—and trained himself in not seeing or not understanding the arguments that contradicted them."