There is a weird phenomenon from both anti-communists as well as a lot of ultraleft and leftcom communists themselves of applying a “one drop rule” to socialism, where socialism is only socialism if it’s absolutely pure without a single internal contradiction. But no society in the history of humankind has been pure, they all contain internal contradictions and internal contradictions are necessary for one form of society to develop into the next.

This is a really good way of putting it. So much of ultraleftism is in fact an idealist denial of basic dialectical materialism.