According to Osho, communism calls for a 'dictatorship of the proletariat' because democracy, dominated by money, preserves the status quo: the rich finance elections, buy politicians and even votes, keeping the poor powerless. Only when the have-nots hold decisive power can exploitation be stopped and a class-divided society be transformed toward classlessness; hence Marx’s proposal—distinct from fascist dictatorships—as a strategic seizure of power by the poor.
Since the rich can control elections, the poor can’t change things through democracy, so communism says the poor must take charge to end exploitation.