Creativity it's a subjective concept. And saying Utada is more creative than ayu is also subjective. Sure you can be creative, but creativity doesn't necesarily equal quality. Many artists are considered such not because they created lots of things, but because they worked hard in one (or may be more) and went beyond than others. And honestly, i think it's better to be really good in just one area than working in many and not being good in any. If you wanna be the best, you have to invest a lot of time and effort to improve your abilities,in whatever you do.
And the grammys... i have mixed feelings about them. The main categories as someone pointed, are very corrupted and basically just focused on what's "hot" on the charts... It's clear quality is not the main standard here, which honestly, makes look the grammys as a joke, with all due respect. (I just can't visualize a classical record in a nomination for album of the year) but in the other hand, they give awards to lots of genders, including latin music, world music, and classical. I think these are the grammys worthy to pay atenttion to.
in my opinion these are the "serious" categories.