Because he sucks.
He placed 10th and lower in many of his last contests because he looked like dry roast shit and then had the nerve to complain about the judges placing him too low unfairly.
And how would you place in a pro show? Oh yeah that's right, you could never qualify in the first place. Even with biased judging Nasser still won the 2nd and 3rd largest shows in bodybuilding and got runner up in the largest show, also a large # of top 3 finishes in many top shows. The man is a legend, and once he achieved those type of placings he can do whatever he wants (enter as many shows even if it's past his prime and doesn't place as well) and nothing will take away from his legendary status that he earned.
To sum it up, a bitter old man that's burned his bridges with EVERYBODY in the industry by talking shit behind their backs while a few weeks earlier he was in pictures with them posing and smiling... now from what I hear he sells protein shakes and clothes at a mall and soiled trunks on ebay and his site.
LOL @ "bridges" - bridges to what? To whom? Nasser doesn't need any "bridges" with people in the industry! He's retired, millionnaire and enjoying life!
And are you "friends" with every single person who happens to be in a picture with you, including people you meet through your profession (if you have one)? Just because he has pictures with them does not mean they are "friends." And how honourable are the people he spoke out against? One who steals money from a friend and never returns it? One who lies to fans that he was attacked by ninjas and therefore can't compete? One who sells fake GH to others? etc.