I’m not a hair band historian but as a woman who grew up in the 80s and really likes all sub genres of 80s music, I would like to throw my 2 cents out there. I was always under the impression that hair bands like Ratt and Dokken liked to head bang. Bands like Bon Jovi and Def Leppard were very pretty. Bands like Twisted Sister and Black Sabbath were shocking. All of them were metal and all of them had long hair but they had very different sounds and personas. I have no idea why that fad was the trend any more than I understand SUPER baggy pants on rappers. I would imagine that MTV helped spread the word that it was “the look” for all of the aforementioned. I feel old now.