Bettleheim's exposure to the concentration camps afforded him the opportunity to observe some of the nature of humanity that few will ever witness again. His education allowed him to objectively analyze those situations and perform experiments in more controlled environments later on. He was very controlling because of his need to prove or disprove a theory without any contention or criticism from his colleagues that had not seen what he had.
Bruno Bettelheim was a genious psychiatrist that was the unfortunate victim of the horrible concentration camps of Adolf Hitler. He was eccentric and some people might think he had some weird tendencies, but those all contributed to making him the special person that he was. He should be remembered in a positive light.
Bruno Bettelheim was a mentally unstable survivor of the concentration camps who had control issues and not a gifted and brilliant psychiatrist. After Bruno Bettelheim committed suicide in 1990, former students of his came forward and spoke of the mental and physical abuse perpetrated on them by Bettelheim while under his care. Bettelheim was also described as being a self hating jew.
Bruno Bettelheim had a lot of different outlooks to the way he viewed things that were not reported to be accurate in anyway. Psychiatry has lots of concepts that go into categories that have to be rationalized. Which means a lot of peers of the same profession could not back is beliefs and thought it could be a real mental issue with him.
Given the information available on Wikipedia about Bruno Bettelheim he obviously cultivated ideas that have been found to be false in the study of psychiatry, so he most definitely was not a brilliant psychiatrist. However, the other option, "simply a mentally unstable survivor of the concentration camps who had control issues," doesn't seem like a likely explanation either.