For us to get any kind of support from the rock 'n' roll counter-culture, which is obsessed by underground music, was extremely gratifying.
I understand that their new record was bought by people who didn't like rock and roll, who only listened to the underground music. So the members of the band felt pleased about it,
Basically, yes. However, the "rock 'n' roll counterculture" does like rock 'n' roll, but only of a certain kind that they consider less commercial than mainstream rock.