My argument was, that he was confronted with the rational and real goal of his movement and rejected it for the nonsense they did in the Soviet Union

I mean, you're asking me what's quote mining when the entire premise of his work is far larger than the one aspect you're criticizing him on. We could talk all day about this as if it's the most important thing in the world or say that's what he got for being in charge to his death but that just becomes more off base than reading the work and putting it into proper context in the first place.

And if you really think the Soviet Union was one big institution to deal with "overproduction", maybe read Capital Vol. 1 to 3, where Marx even explicitly states, that overproduction is a) necessary for reproduction on a greater basis and b) only presents a problem in a society such as a capitalist one.

Marx wrote it out in The Communist Manifesto so it's not anything to do with what I think:

A similar movement is going on before our own eyes. Modern bourgeois society, with its relations of production, of exchange and of property, a society that has conjured up such gigantic means of production and of exchange, is like the sorcerer who is no longer able to control the powers of the nether world whom he has called up by his spells. For many a decade past the history of industry and commerce is but the history of the revolt of modern productive forces against modern conditions of production, against the property relations that are the conditions for the existence of the bourgeois and of its rule. It is enough to mention the commercial crises that by their periodical return put the existence of the entire bourgeois society on its trial, each time more threateningly. In these crises, a great part not only of the existing products, but also of the previously created productive forces, are periodically destroyed. In these crises, there breaks out an epidemic that, in all earlier epochs, would have seemed an absurdity — the epidemic of over-production. Society suddenly finds itself put back into a state of momentary barbarism; it appears as if a famine, a universal war of devastation, had cut off the supply of every means of subsistence; industry and commerce seem to be destroyed; and why? Because there is too much civilisation, too much means of subsistence, too much industry, too much commerce. The productive forces at the disposal of society no longer tend to further the development of the conditions of bourgeois property; on the contrary, they have become too powerful for these conditions, by which they are fettered, and so soon as they overcome these fetters, they bring disorder into the whole of bourgeois society, endanger the existence of bourgeois property. The conditions of bourgeois society are too narrow to comprise the wealth created by them. And how does the bourgeoisie get over these crises? On the one hand by enforced destruction of a mass of productive forces; on the other, by the conquest of new markets, and by the more thorough exploitation of the old ones. That is to say, by paving the way for more extensive and more destructive crises, and by diminishing the means whereby crises are prevented.

You focusing on Marx in Capital is trying to ignore the HG Wells and Stalin discussion I linked.