Whatever became of the summer of love?
spectator.co.uk
spectator.co.uk
Of course, that kind of radical change isn't achieved by smoking pot and playing the guitar in downtown San Francisco. It's achieved by major technological changes that would make such a society even functionally possible, like practically-unlimited renewable energy sources. Needless to say, nobody involved in the 1960s counter-culture movements was in any position to actually implement the kind of changes needed to realize the grand vision of an ideal hippie society. (Some of them tried to do the next best thing, and form their own mini-societies in communes out in the country, all of which ultimately turned out to suck.)
I would also note that another 1960s icon, Gene Rodenberry, at least seemed to realize that the kind of changes needed to implement a hippie utopia would likely only be possible after many other practical societal problems were solved via technology.
Maybe not directly, but a substantial chunk of the hacker culture came from the periphery of it.
"What the Dormouse Said: How the Sixties Counterculture Shaped the Personal Computer Industry" by John Markoff is an interesting exploration of those links.
And some people, like Stewart Brandt, were at the nexus of both. Stewart Brandt as part of the Merry Pranksters which was part of kickstarting the hippie community in SF, as the publisher of the Whole Earth Catalog, assisting Doug Engelbart with the Mother of All Demos, and later as a founder of The Well and more recently via the Long Now Foundation.
Jerry Rubin, dressed very much as you would expect a yuppy to dress, didn't disagree but argued, "And why not?"
So it became a schism: realism vs. idealism, consumption and material security vs. community and spiritual well-being.
Maybe the short answer is, they grew up.
If you're interested you might like BAMN - Outlaw Manifestos and Ephemera 1965-1970 https://www.amazon.co.uk/BAMN-Any-Means-Necessary-Manifestos...