Every American generation has a kind of common outlook or set of existential predicaments. The baby boomers, those spoiled progeny of post-war euphoria, were a narcissistic and hedonistic bunch, prone to wild flights of fancy and blind idealism. They believed that love and not showering could change the world. But as the 60s turned to the 70s and their 20s became their 30s (the age past which no one should be trusted) hippy utopianism became yuppie pragmatism. As the pressures of money and family loomed, most of them had to cut their hair, take a bath and join the ranks of corporate america, still retaining the air of smug satisfaction that they had made a difference back in the day. 

Then there was Generation X, as best captured by Douglas Coupland in his book of the same name. Gen X reacted to the idealism of their forebears and the corporate world that sprung up on their watch with a deep cynicism and cripling nihilism. They created punk, extreme irony, and indie labels; they drank a lot, but didn't do much else. Inevitably, they too had to get serious: indie became grunge, D.I.Y. entrepreneurs became major label hacks, film rebels became Hollywood. Just like the hippies, the subculture became subsumed by the mainstream, but the internal contradictions were even more stark.

It's a fascinating moment in our cultural history — the point where the most anti-everything generation became mainstream — that new documentary Beautiful Losers inadvertantly captures. It tells the story of how a group of underground artists in New York, inspired by punk, graffiti, skate culture and sheer boredom, managed to catch the attention of the world. But instead of putting the scene into context, it plays like a two-hour advertisement for their work and their travelling exhibition of the same name.

This is probably because it is directed by the curator of said exhibition, Aaron Rose, a core member of their circle and their most frequent chronicler. This explains how can you make a film about white middle class kids making grafitti art without addressing the black street culture they co-opted or how you can make a film about artists making adverts for Pepsi-Cola without using the phrase "sell out". These unasked and unanswered questions about class, race and integrity hang so heavy on the film, you're almost tempted to demand them of the screen.

But a few interviews in, it's clear that these people have probably never thought too hard about their role in society. Most are stunningly inarticulate (if not stoned) on camera, and struggle even to explain how being successful makes them feel. Most are surprisingly apolitical and their goals seem to involve retiring to a beach-side town to skate or surf out the rest of their days. Most interviews are conducted while they are walking backwards, or on a swing, or painting compulsively to shrug off the camera's gaze.

This seeming blindness to the world around them is a far cry from the older end of the Gen X spectrum, who were, if anything, hyper-articulate, highly opinionated and politically conscious. They were slackers because their knowledge of the world's shortcomings boxed them in, prevented them from taking anything seriously, even their own creative endeavours — an outlook which made them less productive members of society but much better talking heads in documentaries.

Through archive footage and interviews, the film presents a classic rags to riches narrative, replete with personal tragedy and resolution. But for the most part, the tough times seem to consist of growing up middle class, being bored in the suburbs and picked on in high school — the horror! These are mostly inward-looking stories of personal development: believing in one's self, falling ass-backward into success and not really being able to comprehend it. 

All of which makes them, not the "spokespeople of a generation" you might hope for, but quite endearing characters and entertaining to watch. Chris Johanson is comically spaced and constantly attempting to be profound; Mike Mills is funny and self deprecating; Harmony Korine is by far the highlight of the film with his amusing drug dealer decapitation story. The childlike sense of play and naive take on the world is by turns refreshing and sickening.

You can't, however, fault most of the art. Sure, their crossover style opened the door for a new generation of blandly happy, advertising-friendly graphic design and vapid street art but this travesty isn't on their heads. Underneath all their bright colours and twee motifs there is something darker, sadder and more complex than you might gather from a cursory glance. Margaret Killgallen's painting is smart and sinister. Harmony Korine's work (Kids, Gummo) isn't twee at all; more grotesque. Shepard Fairey, who makes a brief appearance, is perhaps a more "important" artist whose ubiquitous OBEY signs and iconic Obama portrait are simply a part of the urban landscape, even if you didn't know his name. His highly political messages and cogent critiques of advertising and branding, whether or not they succeed, are at odds with some of the more commercial-friendly work on offer in the film.

It's also hard to fault the filmmaking, which is inventively shot, well edited and well presented. It's approached with the same DIY bravado that informs the art; Rose succeeds by disregarding the conventions of documentaries. But, once again, the lack of critical perspective sullies the film. Without any sense of history, even the history of art, it's hard to know why we should care about these stories. The personalities of the artists and the art on display are almost, but not enough, to carry the film.

We should care, however, because once Gen X sells out, what hope is there for Gen Y — the children of the baby boomers (Nathan Barleys, Brooklyn Hipsters and Shoreditch Twats), who seem, perversely, to combine idealism with cynicism through irony? What will the cultural landscape look like when there's no rebellion that is not instantly swallowed up by the mainstream? Conversely, if these artists have found a way to make money without compromising then I'd like to know how! In a time when Banksy is making millions in galleries and graffiti art has become all but legitimate, it seems unnacceptable to do a whitewash documentary like this. Beautiful Losers is an entertaining snapshot of a scene but we'll need to wait for a meatier film to have a definitive portrait.

History will certainly remember the Beautiful Losers' art, with or without this documentary; but it is mainly an art of entrepreneurs and designers, rather than mavericks, revolutionaries and transgressors — there don't seem to be many of those stories left.