That’s because if the boomers were destructive, they were also creative. Indeed, you can make a reasonable case that theirs was the last great burst of creativity in Western history, the last great surge of mass cultural invention. The boomers were the last generation to come of age with some traditional edifices still standing, the old bourgeois norms and Christian(ish) religion and patriotic history, which gave them something powerful to wrestle with, to rework and react against and attempt to overthrow. And because they came of age within a stable-seeming (though not for long) common culture, their revolution was experienced as a communal experience itself, something that united millions of people simply by virtue of their being young and Western in 1965 or 1969 or 1975.

In an essay on “Golden Ages” in his “Prejudices: Philosophical Dictionary,” Robert Nisbet argued that a great period of ferment and achievement often features a “dialectical antinomy.” This is a fancy way of saying that you need ideas and trends and forces in tension with each other (community and individualism, the secular and the sacred, new ideas and settled consensus, younger and older generations) to ignite what he calls “the blaze of creativity.” We can debate just how golden their achievements really were, but in hindsight his description applies to the period of the boomer takeover — it was the tension between a multitudinous younger generation’s utopianism and libertinism and mysticism and an older generation’s attachment to patriotism and family and religion that shaped and stamped the rise of rock ’n’ roll, the rebel cinema of the 1970s, the New Age reinvention of religion, the New Journalism and the postmodern wave in the academy and the libertarian ascendancy in the G.O.P. and more.

In the movies and television, this tension led to an extended reworking, deconstruction and reinvention of classic American genres (the Western, the war movie, the gangster flick, the sitcom), something that happened first in cinema and then extended more gradually into TV. What we often think of as two golden ages — the auteur years in 1970s Hollywood, and then the more recent golden age of television — are really part of the same generational takeover; it just took longer for boomer influence to work itself out on the small screen. But it did eventually: what David Chase did with “The Sopranos” and David Simon with “The Wire,” and before them figures like the just-passed Steven Bochco and Matt Groening and yes, Roseanne Barr, was all an extension and an echo of the era-defining pop cultural ferment that began in the 1960s and took off in 1970s.

But now we are in the twilight of that era — and it is not at all clear that the boomers’ successors are prepared to react against boomer hegemony with anything like the same creativity and vigor. In part that’s because technological and social change has left the rising cohorts of Americans fragmented, polarized, alienated from one another, too divided by belief and taste and language to build something new together. And in part it’s because the boomers themselves contributed mightily to fragmentation, leaving too little standing when they tore things down and rebuilding haphazardly and self-interestedly, bequeathing a spirit of transgression and permanent revolution that’s run out of things to deconstruct and is either feeding on itself, lapsing into torpor, or generating niche forms of radicalism on the further left and right that are too weak as yet to produce revolution or renewal. (Indeed it is not a coincidence that conservatism, itself decadent in this late-boomer dispensation, is desperate to claim boomer culture for its own — think of Ted Cruz’s love of “The Simpsons” or the new pro-“Roseanne” ardor on the right.)

As Nisbet writes in the same essay, golden ages give way to ages of iron very easily. “If there is no community,” then “there is nothing to challenge, nothing to fuel the dynamism” required for a golden age, and if there is nothing but transgression and dissent, there is nothing to give acts of transgression the “purpose, substance and meaning” that make them something more than just puerile self-indulgence. Both problems define our age; everyone fancies themselves a rebel, even Sean Hannity and Donald Trump, but the traditional forms and structures that would give rebellion purpose and clarity exist only through as effigies to be torn down in ritual re-enactments of the original revolution, now decades in the past.