19 and 21 are great, and I’m sure more than a few people wear the jb Bars shirt ironically.
But this isn’t anything particularly new. The mainstream has always been co-opting some elements of punk (mainly the fashion and pseudo-rebellion), while the underground has continued to produce punk bands. The teeny-boppers, fashion magazines, and record labels can keep their mohawks and leather jackets. I’ve got my Minutemen, my Screaming Females, and my Night Birds, and I’m happy.