The problem is this, "stalinism" has infinite intension and zero extension. That is, it means everything and nothing, but it names only nothing.
Put another way, it has negative cognitive content. Just as those who watch TV news have less knowledge than those who read and watch _no_ news, so the user (and the accepting reader) of the word "stalinism" have reduced total human knowledge. They themselves have less knowledge than they had prior to the use; similarly the reader who accepts the word as meaningful as reduced his/her knowledge.
Carrol