I saw them live in Seattle in the old Arena at the science center, and from what I could tell, the audience (and myself) were so drugged out on LSD that it wouldn't have mattered if we were listening to a jet engine. I finally figured that it was the hippy culture and the acceptance of the behavior that goes along with it that made for there huge following, because it wasn't the musicianship.
BTW, thanks for the empathy.