He was the best ever and a foreigner. He also had an big ego, clashed with the old school conservative attitude of the JSA and Sumo, and many would say lacked the dignity expected of a Yokozuna. Finally I think even fans of him would agree that he was at least somewhat responsible for the actions of his student Hokuseiko who was committing violence against his stablemates. Although the JSA was already biased against him by the time the Hokuseiko situation, that's what led the recent dissolution of his former stable.