Well then it becomes to what level. There is a distance between thinking stalin was a good leader and thinking he was unitonically perfect and not being able to be critical of him.
I’ve never met anyone who falls into the second category but I’ve seen a white nationalist anarcho communist so I have no doubt that people who worship stalin exist, and if you are talking about those people than I doubt anyone would disagree with you.
The problem comes from calling them tankies as that term has become almost meaningless like a leftist version of calling someone an SJW.