The "Nation" of Islam was pretty much the black mafia....they threatened fighters, managers, and even Ali especially right around the time Malcom X was falling out with them. They weren't & aren't "nice" people.

Ali was who he was, people either love him or hate him. I think he's one of the most overrated fighters in the history of the sport and his record shows he had many close battles and lost/should have lost many times. People like to assume in the hypothetical matchups that Ali would beat anyone and everyone when he had so much trouble with a 1 dimensional fighter like Joe Frazier (great but 1 dimensional), he got dropped hard by Henry Cooper, he struggled vs Ron Lyle & Ken Norton.

Ali IS an icon of boxing probably most for his celebrity outside the ring as his performances in it and that's just the God's honest truth.