GenZhou

Marxism is supposed to be a scientific theory of development. The point of the proletariat seizing power and nationalizing industry is to resolve the contradiction between the socialization of labor/production, which results from the development of big industry which drags capitalists against their will from complete isolation to complete socialization, and private appropriation. Due to private ownership, a small number of people control the appropriation of resources, but as enterprises get larger and larger, more and more people work together collectively to produce those resources.

This contradiction increases as larger enterprises get until eventually it is no longer sustainable and starts becoming socially unstable and hindrance to further development. The proletariat seizing state power and nationalizing these big industries replaces private appropriation with socialized appropriation and thus resolves the contradiction as it is consistent with socialized production/labor.

The reason I tell you all this is because people often misunderstand Marxism as just "private property = bad," and if you believe "private property = bad," then from that standpoint you would want to abolish it immediately under any conditions. But that's not Marxism, in Marxism, the nationalization of industry is for very specific economic reasons, and so by necessity those conditions must first exist to justify nationalizing industry. And what are those conditions? Heavily socialized production/labor which is a result of the development of big industry.

Hence, you need big industry first in order to justify nationalizing, or else you've abandoned historical materialism for moralism. This is why the Manifesto does not call for the immediate abolition of all private property, but in the program Marx suggests he only calls for an immediate extension of industry owned by the state, and then says the rest can come gradually, "by degrees," alongside developing the forces of production as rapidly as possible.

Why is developing the forces of production important? Because by doing so you encourage more sectors of the economy to develop into big enterprises. If you read The Principles of Communism Engels says clearly that big enterprises can only develop in a competitive market economy, and therefore you cannot abolish private property in one stroke because you have to let the forces of production develop which can take a long time.

This is also why Marx believed you needed the dictatorship of the proletariat. It makes no sense to speak of a state without classes as he viewed the state as a tool of class oppression. He says clearly in Conspectus of Bakunin’s Statism and Anarchy that class distinctions will still exist because the economic conditions that give rise to non-proletarian classes (the decentralization of production due to underdevelopment) would not immediately go away and would likely not go away for a long time.

Lenin understood this too, he warned against the nationalization of small producers multiple times. In The Tax in Kind he says that it would be economic suicide to nationalize the small producers, and in Left-wing Communism: An Infantile Disorder he says that the proletarian state just needs to "learn to live with them" (the small producers). There is just no reading of Marx that gets around the fact that if we take Marxian political economy seriously then the nationalize of enterprises is only applicable to big industry. It is just not applicable at all to small industry.

Mao did start off rather materialist and some of his earlier works are pretty good, but over time as he got old he seemed to move more towards moralism and tried to rapidly nationalize everything even though it made little economic sense. When it was leading to economic difficulties, he thought the problem was bad influences of bourgeois morality and a cultural revolution would help purge those bourgeois moral elements from the superstructure. However, this just led to a practical civil war and was a complete disaster.

When Mao died, the Gang of Four made it clear they had completely abandoned any pretense of being materialist and had just become pure moralists, outright saying that they would prefer China to be poor than to ever allow an inch of private enterprise to operate in the country. The situation was so dire that Hua Guofeng, Mao's own chosen successor, had the Gang of Four arrested. Mao had so many great achievements I don't really like talking much about his failures but this was all a disaster but luckily his successor managed to fix it.

However, "Maoists" think the older Mao's policies were all actually a good thing, that the problem really was moral bourgeois corruption in the superstructure and the only reason his policies failed because he didn't implement them early enough. Maoists insist that any socialist country that actually follows the Marxian path of development has betrayed "true socialism" as "true socialism" according to them would nationalize everything and if there is one iota from private enterprise in your country then you are an evil immoral revisionist capitalist roader.