To me, real punk consists (consisted) of bands of friends/acquaintances of barely educated, marginalized kids circling the drain of nihilism and drug abuse who found some outlet for the anger and despair in simple arrangements of really angry music that gave them some status above the crowds of other kids in the same boat and but not much else PLUS the music industry types who realized that while any given band would rise, produce and disintegrate in at most 3 years, a pretty good revolving door of revenue could be created around calling the scene Punk and riding that wave as long as it lasted. Against that backdrop the occasional legit musician would come along, be a part of all that, then get bored and actually start creating some music. This was known as selling out, but would form the nucleus of "pop-punk" bands like The Offspring, NoFX, Green Day, etc.
I was a big fan of Punk when I was 16-19, but more because I was a testosterone soaked, socially marginal kid than because the musical structure, melodies, and lyrics were so transcendent. Truth be told, even then I found it boring unless it was at a show or a club where there was the mob mentality to lift me out of my skull. Metal and Industrial music on the other hand was actually something I could listen to for more than 3 songs in a row.