@Mamradpivo and @buster have the keys to the puzzle.
Jerry Garcia’s death did deal a tremendous blow to the distribution channels. At this point, the internet was just beginning to become commonly used, it was only a few years into the World Wide Web, but it wasn’t something that most Deadheads used. Although a contingent of Deadheads were the among the first ever to use the internet, with the Whole Earth Lectronic Link.
And then a few years after Jerry died, Leonard P. got busted, and his 10 million hits of acid got seized. And apparently, that was pretty much all the LSD in the nation. By now, the Web was firmly in place, and the distribution channels could have easily been rebirthed. But Leonard P.‘s imprisonment has prevented all that.
Almost a whole generation has gone by without curious souls being able to look within.
At least with this route.