I think we all need to realize that Ayumi's popularity isn't as it used to be and that one day, someone new will replace her as the top j-pop queen (just as Ayumi replaced Namie, etc). It doesn't mean she'll disappear altogether but we'd see less of her. Avex does depend a lot on Ayumi for their revenue, which will be bad when her sales start to inevitably decline. As for her ego, well, I wouldn't be surprised. All famous people have some sort of a superiority complex (some less than others). It's almost impossible to stay normal when everyone is willing to do anything for you.