That doesn't conflict with anything I said. The Beatles (or Elvis or Sinatra or the Beach Boys or Easy Rider, etc etc) were a reflection of societal changes, not the cause of them. As for the world being nicer if people had more of a Mary Poppins attitude, sure that would be nice, but the...
I don't see pop culture catch phrases as "changing the world". No one said the world was "changed" because kids were buying Star Wars toys, any more than the world was "changed" because kids bought Daniel Boone coonskin hats or carved Zs in school desks back in the 50s, or bought Beatles boots...