Yup.
On something you said though. " ....until they can teach the uneducated masses how to do things like running factories,...."
The proletariat are already making stuff in the factories. They are running production, but they don't own it.
So for the proletariat to own the means of production, all you have to do is get rid of the Bourgeoisie who own it.
Marx did not appear to understand risk assessment though, just simple " what if ?".
For example, if we get rid of the Bourgeoisie who own the means of production, and give it to the workers, how do we stop the workers becoming a new elite.
And I think that is where his whole manifesto falls over.
As you say, certain groups can latch on to parts to justify themselves. All the new elite have to say, is we are not Bourgeoisie, we are proletariat.
And yes, when you say ".they just haven't got round to it...ever in the history of Communism", I totally agree. I don't think they can't, not without re-writing all of Marx, and actually defining what stuff means.
For Example. " To each according to needs".
The USSR done that, the CPC do that. But because " needs" was never defined, the system can't work. The elite leaders define what needs are, not Marx. And the leader's needs are very big.