The reason people today do not move toward better taste in music is the mind-body dichotomy, a cultural anti-integration between our animal nature and our higher, human nature. Rock music is not mid-level music in the transition from childhood to adulthood; that implies that it is wholesome and integrated, but just less complex. The entire essence of rock music is the "liberation" of wild animal impulse from the control functions of higher intelligence. So it is not part of the proper and healthy and normal process of development; it is moving in the opposite direction, toward physicalism and animalism, constantly reinforcing a negation of the higher faculties.
The essence of rock music is the boiling loins blowing out the brain. It is not just unsophisticated--in fact it is highly sophisticated in its means of accomplishing its aim which is the destruction of morality and humanity.
(Cue the arguments that rock star X has has "classical training," that rock star Y has "very advanced guitar finger technique," that rock song A has "complex harmonies," etc--all of which are just mechanistic, out-of-context technical factors which lose the overall meaning and message of the music.)