Not saying he is a hero. Never have. He took what could be considered a courageous stand by not going to Vietnam. The idea that he was a cowardly draft dodger can certainly be backed up also, I don't deny that. I'm sure many more stories about his character flaws will be coming out soon enough, as they are plentiful.... It's the American way, it seems, to lionize somebody for a week or two after their death and then start exposing all the skeletons....
You are assuming he'd have actually gotten close to any combat... The Army wouldn't let Joe Louis or Elvis (had there been a war going on during E's hitch...) anywhere near a flying bullet... People like Jimmy Stewart had to basically demand actual combat duty...
Yeah, I don't get that part of the puzzle either....having spent a few hours last night reading up on this whole subject I'm pretty sure he (and his $$$$) was being used by the NOI to further their own cause. I'm not convinced his IQ was truly that low. Maybe it was and he was intelligent in other ways (how smart do you have to be to go 'round bragging about how great you are?) but we'll probably never know whether it was an act or a fact...
In any event, he was certainly one of the more controversial figures of the 20th century and folks will be arguing this point (and whether he truly WAS "The Greatest", which I don't buy... but that's another argument) forever...
Several good links and clips in here: https://theringer.com/muhammad-ali-syllabus-read-watch-video-174a6bea681a#.wus6oo6bp
I'll link this one separately because I especially reco it: http://www.si.com/boxing/2012/01/17/muhammad-ali-70th-kram
"The Right Hand Lead Round" [video=youtube;ZbAY85eQQ30]https://www.youtube.com/watch?v=ZbAY85eQQ30[/video]
A lot of different reasons. The rise of NFL football and the complete lack of infrastructure are two notables. It used to be HUGE, though.