i can't say i love all of her classic ballads, 'cuz i'm not a ballad person, but lots of them had grown on me over the years. I totally enjoy beloved and Why. Sure they sound like a lot of other j-pop songs, might be boring for some, true they aren't very special instrumentally, but somehow I find something that catches my attention, there's something melodicly so beautiful that makes me like them. Plus her voice sounds so much better in both of these, I love how her vibrato changed into somethign so naturally flowing, that makes me appareaciate them even more.
Sometimes artists just need to go back to basics, to their roots, so they can later explore what's new & fresh for them, you just get borred of playing around with things after a while.
Plus for some songs you just have to "grow up" yourself to start liking them.