Every Vietnam Veteran ( along will all that served) has the right to express their opinion on Ali's refusing to serve, but I hope they also object to the others that are now held in high esteem by the American public that found a way to avoid serving in Vietnam
There were many that found a way to avoid serving in Vietnam, through college deferment and on religious grounds.
Romney supported the Vietnam war, but chose to go on a Mormon mission to France rather than back up his support.
Dick Chaney used multiple deferments that kept him out of the draft as other politicians (Democrats or Republicans) did at the time.
Ali used the court system to prove his point and didn't try to avoid the consequences of his actions,but embraced the right to state his opposition legally .
Some of the things Ali said at the time doesn't seem right, but Ali did what he believed was right and fought for his right to believe that way.
He would have had an easier time , in my opinion, gaining support if he wasn't a Black Muslim (Nation of Islam) that was looked on as a radical black group and wasn't considered a mainstream religion.