Hmmmm. In high school for me it was a look and attitude rather than mindset. It was steeped in groupthink as well and othering too. It wasn’t much different in function from other in-groups out-groups. So really YMMV. Yes there were likely “intellectual punks” just like there was “intellectual rap/hip-hop” and there were thoughtful and nice jocks but the vast majority was just run of had mill stuff.
I definitely remember this as well, but I also think that a lot of that is part and parcel of high school. Young people trying to figure out where they fit in, falling into the usual pecking-order-type behavior that so often results from insecurity, etc.
But I also know that as I got a little older (into my later teens/20's) there were definitely a lot of fellow "freaks and geeks" that were drawn to punk and other ostensibly "outsider" music and art forms.
I think a lot of it had to do with being the sort of people who either never had it in them to be part of the "in group" and were forced to learn the joys of exploration/experimentation, or those who just had a natural curiosity and maybe a bit of a contrarian outlook that led to that sort of thing.
But yeah, I definitely remember quite a few times being brushed off by the other "alt" kids in school because despite sharing a lot of cultural interests, I had fairly strict parents and wasn't allowed to dress "wild" (or what high school kids considered "wild" at least).
It's a bit of both, but the general trend over time has been away from the mindset and more to the look/groupthink. In particular in the late 80s through 90s. Granted one of the most iconic OG punk bands (Sex Pistols) were literally formed to sell a look.
The punk ethos is a real thing. And the punk look is a real thing. Sometimes they overlap. Sometimes they do not.
