Lets look at some other facts
After winning the gold medal in the olympics he was refuesd entrance to a restaurant in his home town due to his colour
The segregation at the time gave rise to extremist groups such as the nation of islam
Under pressure from this group he still refused to cut ties with his coaching team and eventually cut ties with the nation of islam.
He refused to be an unle tom and refused to join an army he thought was carrying out an unjust war even at the cost of hi career.
He was symptematic of his time and of course he had faults but he recognised them himself. As for Joe Louis friend of the white man post some facts about where he ended up and how his life ended, hardly the dignified end you imply.
Ali was more than a fighter he was an iconic symbol. Che Guevara had loads of faults but he too was an icon and how dare people like this stand up to an unjust society that abused their people both black and Latin.
If your talking most succesful heavyweight then Marciano, as for the greatest ever boxer probably sugar ray robinson.