I highly recommend Nick Tosche's "Hellfire," about Jerry Lee Lewis at his peak. Lewis was raised in that fire and brimstone deep southern version of religion, and Tosche's writing alternates between dark, mock biblical passages and the sheer exuberance of Lewis' stagecraft (and lunatic offstage antics). This book captures the good v. evil theme of rock and roll in a way peculiar to its time and place; to me, the so-called 'dark side' of much later acts like Black Sabbath and Alice Cooper were more schtick than reality (much as I love certain of those albums).
I would feel a real loss without some of the music that grew out of the early rock and roll era, including late 60's- early 70's psychedlia. Just to name one album that has been a constant for me since it was released: Spirit's 'Dr. Sardonicus.' Or the soaring jazz inflected drive of the Allman's when Duane was still living.
I won't judge Schubert- his tastes and views are his own. I doubt it has much to do with age. Look at some of the music greats: Chris Blackwell, who brought us so much on Island in the early days, now in his late 70's; the late Phil Ramone, whose discography of production and engineering spanned many generations of great music making; Clive Davis, Ahmet Ergtegun, Mo Ostin and so many others of a 'certain age' who were (and still are) making great music possible.