You'd also have to apply regional, economic, and temporal discrepancies as well. A "head" in southern california could have easily become a "burnout" quicker than the "head" in say, Idaho. Add in the slow migration of independent music to your midwest "heartland" regions, and I'm willing to bet there are still "heads" in montana to this day, and we may never have a "punk" sighting in that part of the country ever.