In the early days, psychedelic drugs were not taken for "fun." I still don't quite understand the notion of taking it for "fun." Altered reality is often a terrifying place. Sometimes, however, it offers beautiful and mystical experiences. It opens one's mind to new ideas and alternate consciousness. It puts many in direct contact with the creative imagination.
We were foolish and naive, thinking we could shortcut the quest for numinosity and creative bliss. We played with fire, wide eyed and unprepared. The Old Gods were awaked by all that ecstatic devotion. Those primitive forces are both good and bad. They act according to their own nature. People died. But the music from that time period was most certainly inspired.