Because it is all about the Tower and the law and the office of the Amyrlin. All that you are saying about what Siuan used to be has now been transfered to the person of Elaida - hence their reluctance to follow Siuan's plans.

Who voted Michael Jordan a great player in order to break a deadlock between several other candidates? Michael Jordan's ability and position as the best was proven, demonstrated and earned. And if Michael Jordan in a wheel chair kept trying to play guard for the Bulls, he quickly would be laughed off the court. Likewise a former president of the US who tried to act as if he still possessed his authority. It would be more like a president who lost his re-election bid because of disastrous policies and a public scandal and tried to address a meeting of the party leadership as if he were still in Oval office & insisting on the respect and deference that would be due. Those things are trappings of the office, not the person. What office did Michael Jordan hold, that brings the acclaim and respect of an excellent basketball player with it? Michael Jordan's fame and accolades came with his person and his own deeds. Siuan's authority and prestige were all functions of her office. While she might have exercised such power and status more than the typical holder of the office, if anything, that would make her a MORE likely target now that she no longer holds them. Sort of a "not so tough, NOW, are you?" mentality.

Except, not. A fighter pilot in the Air Force is hardly the latter anyway. On the other hand, a high-ranking military officer, cashiered in disgrace for exceeding his authority, would receive much the same reception Siuan encountered in Salidar.
If you insist on comparing her to a celebrity, try an actor whose looks have gone, and whose last few films were a flop, whose personal life has become the subject of late night TV hosts' monologues and ex-lovers' tell-all interviews are the cover stories of the supermarket check-out rack, barging into a studio meeting during an industry crisis and expecting the royal treatment.

Only in your mind.