The proletariat is the least conservative element of society. The bourgeoisie is the class of people who appropriate the labor of wage workers through their control of the means of production.
Dictatorship is organized force.
According to Marxism, all governments are dictatorships. When classes are abolished, it may be possible to have no dictatorships because governments will be abolished and replaced by voluntary cooperation. We communists admit to having dictatorship governments until we achieve our goal of classlessness. It's a matter of accountability. Dictatorship of the proletariat is the government of socialism.