I think almost everyone in the world knows who Ayumi is unless he or she has been living inside a shell. (LOL)

Actually it's difficult to categorize Utada's music. It's not fully pop or rnb, it's too diverse. Besides, most of her great songs don't sound very mainstream. They're not those kinda music that you will instantly get hooked on to after listening to the first chorus. I'm not sure about you guys but as for me, it takes a few times of playing her songs for me to fully appreciate them. This is also a reason why I don't feel like I'm listening to pop when I play her music, it feels very... different.

Let's just face it, it's hard to break in. I'm not trying to generalize but the audience that she's trying to target are mainly people who listen to songs that sound super mainstream. It'll be tough and maybe it's also because of Xenophobia, like what Hazumuchan said. There are too many factors for us to look into.