While it is possible that there are individual Scientologists who are stupid, crooked or mean, that is certainly the exception, not the rule. Thinking of Scientologists as suffering from some sort of mental defect merely prolongs prejudice, which itself is a mental defect.
Scientology is not a natural, inherent mental characteristic of a person. It is an infectious, artificially-produced view of life. As near as I can tell it seeks out points of weakness in people to turn around and use against them and others. So if people been affected by Scientology, that only proves that they are human, like you and me and and our friends and families.