I don't think people are bored of Ayu at all. Some people are just bored of saying "I love Ayu! She's the best!!! <3" , IMO. And maybe some of them think they are interesting when they say "she is loosing her shine.. bla bla, bad songs, bla bla.."
But I'm not bored of it, I LOVE HER SHE IS THE BEST!!!