"Stalin did nothing wrong" is a dogwhistle for friendless internet weirdos. It's "stan LOONA" for the reddit left. It's a completely useless position that evidently does not inoculate you against fascism, doesn't connect you to any currently existing struggle against capitalism, and doesn't ingratiate your politics to any segment of the population outside the people who already say it. In this case, people who aren't communists are using it to trick people who are communists into thinking they're communists because they said the thing communists say.