I know this is something that is hotly debated, but one of the reasons I have trouble listening to Ayu anymore is her voice quality. I feel like she is struggling to sing these days (not that she doesn't want to, but that her vocal chords are failing her), and that's too painful for me to deal with. I can't imagine what she herself must be going through if she feels the same way about her singing as many people have come to feel about it.
And this is not to say I think her voice has gotten progressively worse since her debut. My favorite vocal era of hers was My Story, and I'm in love with everything through Secret; while Guilty, Next Level and Rock'n'Roll Circus, though not as fantastic, still appeal strongly to me. Love Songs was a huge comeback for me musically - Love Song and November are just brilliant - but vocally I felt there was a kind of nosedive that has only gotten progressively worse.
Since Party Queen I've just been too depressed with the situation to want to listen to her stuff. And although - for me - Party Queen was her worst album to date, there are still some stellar tracks on there that I think would have been more amazing if her voice wasn't falling apart.
I know some people like her voice still, and that's great. It's absolutely obnoxious when people who've lost interest in her or don't like her stuff try to convince everyone else to feel the same as they do. But I can understand why people are not as charmed as they used to be. And I can't pretend, and it makes me too sad
I still try and sample every release but it's really been hard.
Meanwhile, I've lost interest in her performance art when she became overly theatrical. I like her more honest, "sing and move as the music takes you", rather than as rehearsed-to-death, performances.
Also, an aside that really wouldn't matter if I was still into her current music - her photoshoots and image have felt especially fake lately (mostly since Rock'n'Roll Circus). Even album art. I know it's part of the style these days, and she has always done radical things, but compared to back when I have trouble connecting with her visually. I felt like her rawness and honesty really came through in the past - but it just seems covered up these days.