Neither of the two are (or were) simply "Marxist" though. The USSR under Stalin was Stalinist and otherwise Marxist-Leninist at best. China was Maoist and is now more recently Dengist. These ideologies all claim to build on Marx to various degrees (as does Vietnamese Ho Chi Minh Thought for that matter) but calling them Marxist is a stretch. I'm explicitly referring to the Bolsheviks to make a general point about vanguardism which all of these ideologies are built on.
I also explicitly said that the USSR and China are/were aspirationally communist, i.e. their stated intent was to build communism. This is why most of the Eastern Block described their various forms of authoritarianism as "actually existing socialism" or "real socialism" and dismissed anyone criticising them as "utopian", i.e. demanding the impossible. They never claimed to have succeeded at building communism - in fact they mostly argued that the only way to achieve communism would be a universal global transition and this was the motivation behind co-opting foreign communist movements and bringing them in line.
Communism as used by Marx is a class-less, state-less society. Anarchists extend this definition to the abolishment of all power hierarchies (with class and the state just being two examples). Lenin, Mao, etc did not fundamentally change the meaning of "communism", they just argued that it's the (perhaps impossible) end goal and therefore justifies the means.
If you want to use a term to describe the actual rather than aspirational ideology of the USSR and China, the term is "state capitalist", i.e. the state (or party) takes over the role of the owning class. Under these states, the state (or party) holds control and governance over all private property. In the USSR this was mostly implemented as the command economy, under Dengism this also makes use of "special economic zones" were individuals are allowed to act as private property owners as under capitalism but the state is always at liberty to revoke their ownership and reintegrate this property under state control.
Orwell was an anarchist and a supporter of the Spanish anarchists during the Civil War. The USSR deliberately prioritized ideological alignment over defeating the fascists and explicitly turned on the Spanish anarchists. This is one of the most important factors in his resentment towards the USSR and similar "communist" systems. In this context the nuances of Marxism-Leninism-Maoism, Marxism-Leninism, Stalinism and other forms of authoritarianism and vanguardism don't really matter.
I also explicitly said that the USSR and China are/were aspirationally communist, i.e. their stated intent was to build communism. This is why most of the Eastern Block described their various forms of authoritarianism as "actually existing socialism" or "real socialism" and dismissed anyone criticising them as "utopian", i.e. demanding the impossible. They never claimed to have succeeded at building communism - in fact they mostly argued that the only way to achieve communism would be a universal global transition and this was the motivation behind co-opting foreign communist movements and bringing them in line.
Communism as used by Marx is a class-less, state-less society. Anarchists extend this definition to the abolishment of all power hierarchies (with class and the state just being two examples). Lenin, Mao, etc did not fundamentally change the meaning of "communism", they just argued that it's the (perhaps impossible) end goal and therefore justifies the means.
If you want to use a term to describe the actual rather than aspirational ideology of the USSR and China, the term is "state capitalist", i.e. the state (or party) takes over the role of the owning class. Under these states, the state (or party) holds control and governance over all private property. In the USSR this was mostly implemented as the command economy, under Dengism this also makes use of "special economic zones" were individuals are allowed to act as private property owners as under capitalism but the state is always at liberty to revoke their ownership and reintegrate this property under state control.
Orwell was an anarchist and a supporter of the Spanish anarchists during the Civil War. The USSR deliberately prioritized ideological alignment over defeating the fascists and explicitly turned on the Spanish anarchists. This is one of the most important factors in his resentment towards the USSR and similar "communist" systems. In this context the nuances of Marxism-Leninism-Maoism, Marxism-Leninism, Stalinism and other forms of authoritarianism and vanguardism don't really matter.