They also got called KPD-Ost, right?
Anyway, found them: k-p-d-online.de/ Still alive.
If those are the mummies, then - yeah. Join either of them. They are sufficiently Stalinist ML.
Right-wingers are cargo-cultists. Of course they don't have any sort of consistency or coherency. They don't need ideology to provide practical solutions. It's there to LARP on a grand scale, like Reich did with Aryans. To distract people. To tell them stories.
But Left actually uses ideology. It is needed to understand how to make shit happen. And to make it happen, you need to learn things. To understand how things work.
And so people get this "weird obsession" for the same reason we have physical laws named after dudes who died two millennia ago. And you can try telling me, that those laws do not have any relevance today. I'll have a good laugh. You need to put labels on things.
Like the law of Archimedes is.
Pretend that you are going to fight with someone, and he promises that he will treat you nice if he wins, provided that you do not bring any weapons to the fight. What will you do?
But the question is not people. People (who will be organized) will get offered practical solutions, without "Stalin said so" or "Lenin tried it and it worked" (unless they like Lenin or Stalin already).
The question is you personally. Do you want to learn anything? Because this is the logic that says "since most people think that Earth is flat, I shall not learn anything that contradicts it".
Soviet Union was the greatest success of Socialist movement. If you are pretending that it wasn't, you either have a very Utopian idea about Socialism (i.e. "it is effectively impossible in my lifetime and I should not even try doing anything about it") - which is no different from SocDem (Venezuela), or some cargo-cult nonsense a-la Posadism. And in the latter case you'll be lucky if you don't actually get to pull anything off, because result will be Makhno's Free State/Cambodia (AnCom/LeftCom).
Moreover, USSR had at least 5 different stages: War Communism, NEP, Planned Economy, Bureaucratic "Socialism", Perestroika. That's 5 different kinds of Socialism, each different from modern realities and different from each other. There is literally no excuse for anyone interested in Socialism not to learn anything about USSR.