Then use another example from your list. North Korea is a totalitarian dictatorship. It's not exactly clear whether its woes are the result of its economic system or its form of governance.
The dictatorship of the proletariat is not communism. Not even for Marx. It is the state before communism, in which the proletariat makes changes in society so that communism may take place.
Most ideologies and political or economic ideas have had their names subverted to mean something different by opponents (democracy, republicanism, communism, anarchism, capitalism...). That doesn't mean that if you speak in the "formal sense" you can decide to use whatever meaning you prefer.
edit - adding 'in the formal sense' to your post doesn't really change things. Formally, communism is supposed to be a developing theory, which is part of the reason for Marx famously saying that he wasn't a Marxist. Formally, communist theory, as envisioned by Marx, was never meant to be frozen as dogma, but rather relentlessly self-critical. Whether he was right or not is a seperate issue, but you are seriously misrepresenting his ideas.
Specifically, capitalism is the 'dictatorship of the bourguise,' so it needs to be counteracted by a dictatorship of the proletariat. Within the governing body, democratic councils run things. To draw a parallel to today's concept of 'dictatorship,' think of it this way: one class has absolute, total rule of things. But a class is made up of many people...