I think what people don’t fully understand is that Marxism is meant to be scientific. That means that there will likely be many imperfect and failed attempts at building a socialist society before one comes along that is stable enough to outlast outside interference from capitalist states.
As such, most people I know who like the USSR are also it’s biggest critiques. Unfortunately, there is so much misinformation about the USSR that most discussions about it online are just about delineating truth from propaganda.