Actually, no, Nasser was not dissed! Nasser dissed the ASC promoters by not attending when he was expected to. Nasser couldn't give a rats ass to go there and get recognition onstage as a past winner, so why would he give a crap if his name is announced or not?
The reason Nasser didn't go was he disapproved of the manner in which the promoters invited athletes - they didn't give formal invitations but simply spread by word of mouth that all past winners are expected to be onstage. They also expected all winners to pay for their own expenses, book their own flights/hotel, etc. Very unorganized and cheap on the part of the promoters. Just one of the many differences between bodybuilding and other sports.