>>84387
>I don't think Marx ever justified why he used the LTV
Capital vol.1, chapter one.
>he never justified his social necessity criterion ("Why isn't useless labor valuable? Because it isn't valuable.")
I think you're confusing terms here… When Marx talks about socially necessary labor he means the average amount of labor necessary to produce something, not whether or not a certain type of labor is valuable in the market.
>he presented several iterations of the stages of history
His theory of history is pretty weak, imo.
>he had no coherent vision of communism
True
>extraction of surplus value, alienation, and - what he actually talks about the most - low living standards
Exploitation, alienation, and immiseration are not moral arguments though.
>I don't think he anticipated any counter-arguments that would later be used against his position
Marx repeatedly addresses counter-arguments in Capital in almost every chapter.
>You have to do it if you want to be taken serious by commies.
I think intelligent criticisms could be made of Marx by non-Marxists but they're very rare. Almost all criticisms of Marx from non-Marxists are based upon misunderstandings of his key concepts. (muh mudpies) There's a lecture on youtube by Steve Keen about the Marxist concept of value and it's very, very good and he actually understands the concepts involved while disagreeing with key parts of Marxist theory. Aside form that it's very hard for me to think of anyone else whose criticisms aren't strawman arguments.