My understanding from posts here is schubert was a vet and witnessed horrors in his life that set him on the path of seeking to soothe his soul. To him classical music and Bach served that purpose as it does for many.
Yes he believed rock music did not fit his mold as something that uplifted humanity. Note I am an avid fan of all music genres and that includes rock pop and even rap/hip hop. I believe pop music is a mixed bag in terms of its influence and that music affects everyone differently and do not pass judgement.
To each his own. Schubert is/was a kind soul with good intentions and very strong beliefs. Good for him! I respect the man greatly.