Why do they want authoritarian communism? Well, I haven't spent months reading Marxist theory, so they probably won't think I'm able to do their arguments justice. For a "better" (and much longer) explanation, ask at hexbear or lemmygrad.
Their argument, as I understand it, seems to be that the USSR, China and North Korea really aren't as bad as Western propaganda suggests. American imperialism is much worse, especially outside of the imperial core, North America and Europe. Also, the people that do get oppressed in AES (actually existing socialism) states mostly deserve it for being capitalists or fascists or libtards.
I'd argue that a "dictatorship off the proletariat" inevitably leads to a small group seizing and holding on to power. They seem to believe that eventually the state will wither away and give rise to Real Communism.
The only way it's going to make sense is if you watch it in chronological order. So you have to start with Enterprise.