Do you think the Clash were a punk band? Assuming the answer is 'yes' (and if it's not, we're in the wrong thread, or on the wrong planet) let me ask you what "definite style of music" that is on London Calling, or Sandinista! Because I sure as hell couldn't describe it using one pigeonhole.
It doesn't matter how SST records, those kids with the giant stand up Mowhawks, Avril Lavigne or Blink 182 define punk. It was defined by the people who started it, and they were all over the map in terms of styles and influences.
I agree that the original punk bands had a lot of individuality, Lydon likes to point that out when dissing the cookie cutter punk bands of today, but still there is a definitive style of what punk music is just like there are definitions of country rock, heavy metal etc.
What bugs me is people seem to apply that punk was just an attitude/philosophy or fad and had nothing to do with musical innovation. The band that really created and is probably the most influential is the Ramones. You would not have to see a picture of them to know something radical was going on, especially at the time. It was the most shocking album I'd heard because-songs were two minutes long, lyrics was sometimes 3 lines, and NO GUITAR SOLOS!
So it sometimes apears people think it was just guys with weird hairdos being obnoxious but it's not the case.
So when people say Dylan or Cash or whomever was a punk, you can argue in attitude but no they did not make punk music or would they want to be considered that way. No one would take a heavy metal band and say "Oh, but they're country rock in spirit."
And the Clash first album is punk after that they became a rock band or at least made music that would mostly fall in other catergories.