About a decade ago, I ventured my opinion that the adult multitudes queueing for superhero movies were potentially an indicator of emotional arrest, which could have worrying political and social implications. Since at that time Brexit, Donald Trump and fascist populism hadn’t happened yet, my evidently crazy diatribe was largely met with outrage from the fan community, some of whom angrily demanded I be extradited to the US and made to stand trial for my crimes against superhumanity – which I felt didn’t necessarily disprove my allegations. Ten years on, let me make my position clear: I believe that fandom is a wonderful and vital organ of contemporary culture, without which that culture ultimately stagnates, atrophies and dies. At the same time, I’m sure that fandom is sometimes a grotesque blight that poisons the society surrounding it with its mean-spirited obsessions and ridiculous, unearned sense of entitlement. Perhaps this statement still requires some breaking down. Concerning the word “fan”, I first encountered this contraction of “fanatic” during childhood, in a television documentary on the phenomenon. All I remember is the weary spouse of a woman devoted to the late Jim Reeves, sitting in a family home that had become a mausoleum of memorabilia, and mournfully accepting that his wife had only married him because his name happened to be James Reeves. Soon after that, the word passed into common usage, although only in the milder sense of somebody quite liking something, and without the connotations of a person listening to Distant Drums on endless replay with the curtains drawn, or a cultist running wild-eyed from the treeline waving a machete. “Fan”, then, meant merely “enthusiast”, but sounded less Edwardian. Quite liking comics, aged 14 I thus became a comics fan with my discovery of British fandom, which was then still gummy-eyed and fresh out of the egg. The first convention I attended in London, in the basement rooms of a Southampton Row hotel in 1969, was tiny and inspiring. The attenders barely totalled a three-digit number, almost all of them some few years short of legal drinking age. The comics companies, having no monetary interest in a handful of penniless teenagers, went blissfully unrepresented, and the only industry celebrity that I recall was the sublime and sweetly unassuming genius Frank Bellamy, passing Dan Dare or Garth originals around, appearing wonderstruck that anyone had heard of him. The only thing uniting the assembly was its passion for an undervalued storytelling medium and, for the record, the consensus verdict of the gathered 15-year-old cognoscenti was that costumed musclemen were the main obstacle preventing adult audiences from taking comics seriously. Of that hardly-a-hundred schoolkids, office boys and junior librarians, the great majority were actively involved in their pursuit, publishing or contributing to a variety of – for the most part – poorly duplicated fanzines, or else going on to work professionally in the field, such as Kevin O’Neill, Steve Moore, Steve Parkhouse or Jim Baikie, all of whom were downstairs at the Waverley hotel that weekend, keen to elevate the medium that they loved, rather than passively complain about whichever title or creator had particularly let them down that month. Of course, this was the 1960s and the same amateur energy seemed to be everywhere, spawning an underground press, Arts Lab publications and a messy, marvellous array of poetry or music fanzines that were the material fabric of that era’s counterculture; flimsy pamphlets as important and innovative today as they were then, although considerably more expensive, trust me. Soon thereafter, caught up in the rush of adolescent life, I drifted out of touch with comic books and their attendant fandom, only returning eight years later when I was commencing work as a professional in that fondly remembered field, to find it greatly altered. Bigger, more commercial, and although there were still interesting fanzines and some fine, committed people, I detected the beginnings of a tendency to fetishise a work’s creator rather than simply appreciate the work itself, as if artists and writers were themselves part of the costumed entertainment. Never having sought a pop celebrity relationship with readers, I withdrew by stages from the social side of comics, acquiring my standing as a furious, unfathomable hermit in the process. And when I looked back, after an internet and some few decades, fandom was a very different animal. An older animal for one thing, with a median age in its late 40s, fed, presumably, by a nostalgia that its energetic predecessor was too young to suffer from. And while the vulgar comic story was originally proffered solely to the working classes, soaring retail prices had precluded any audience save the more affluent; had gentrified a previously bustling and lively cultural slum neighbourhood. This boost in fandom’s age and status possibly explains its current sense of privilege, its tendency to carp and cavil rather than contribute or create. I speak only of comics fandom here, but have gained the impression that this reflexive belligerence – most usually from middle-aged white male conservatives – is now a part of many fan communities. My 14-year-old grandson tells me older Pokémon aficionados can display the same febrile disgruntlement. Is this a case of those unwilling to outgrow childhood enthusiasms, possibly because these anchor them to happier and less complex times, who now feel they should be sole arbiters of their pursuit? There are, of course, entirely benign fandoms, networks of cooperative individuals who quite like the same thing, can chat with others sharing the same pastime and, importantly, provide support for one another in difficult times. These healthy subcultures, however, are less likely to impact on society in the same way that the more strident and presumptuous fandoms have managed. Unnervingly rapidly, our culture has become a fan-based landscape that the rest of us are merely living in. Our entertainments may be cancelled prematurely through an adverse fan reaction, and we may endure largely misogynist crusades such as Gamergate or Comicsgate from those who think “gate” means “conspiracy”, and that Nixon’s disgrace was predicated on a plot involving water, but this is hardly the full extent to which fan attitudes have toxified the world surrounding us, most obviously in our politics. Elections that decide the fate of millions are conducted in an atmosphere more suited to evictions on I’m a Celebrity …, in which contestants who are insufficiently amusing are removed from office. Saleability, not substance, is the issue. Those who vote for Donald Trump or Boris Johnson seem less moved by policy or prior accomplishment than by how much they’ve enjoyed the performances on The Apprentice or Have I Got News for You. And throughout the UK, we’re now familiar with what a Stephen Yaxley-Lennon fan convention looks like. An enthusiasm that is fertile and productive can enrich life and society, just as displacing personal frustrations into venomous tirades about your boyhood hobby can devalue them. Quite liking something is OK. You don’t need the machete or the megaphone. Candidly, for my part, readers would have always been more than sufficient. The Great When by Alan Moore is published by Bloomsbury Publishing . To support the Guardian and the Observer buy a copy at guardianbookshop.com. Delivery charges may apply.