I think there's a range of frequencies/vibrations of sound that our brains naturally enjoy. We know right away whether it sounds good or bad to us, the same way that we do with how food tastes. We can develop our taste and understanding of music, but we'll always have a starting palate of sound preferences.

"More complex and interesting" is subjective. Pop music is music that appeals, sonically and thematically, to the broadest spectrum of listeners. That requires its own genius to achieve.