The aesthetic style associated with Dave Eggers, the memoirist, journalist, novelist, and literary entrepreneur, has always been a slippery thing — instantly recognizable yet somehow difficult to describe. It’s informed not only Eggers’s own writing (he’s most famous for A Heartbreaking Work of Staggering Genius, an account of raising his younger brother after their parents’ sudden death) but a larger literary world, which has gathered itself around periodicals like McSweeney’s and The Believer and their various affiliates. In Eggersland, the persistent aspiration seems to be enthusiasm tempered by self-awareness — a style that’s hortatory but self-deprecating, idealistic but non-dogmatic, childlike but not childish, touching but not maudlin, and clever but not twee.

Above all, though, the Eggersian writer tries to be kind, and life-affirming, and nice. Perhaps the most famous piece ever published in The Believer featured Heidi Julavits, a rising young novelist, bemoaning the triumph of “snark” in the book-reviewing world and pining for critics more interested in “fairness and rigor” than “destructive clear-cutting.” Eggers himself, amid an (extremely well-mannered) online spat with one such clear-cutter, described his intellectual pole star as the hope that “the literary world could be one of community, of mutual support, of spirited but nonviolent discourse — all in the interest of building and maintaining a literate society.”

When this works, it works: Kindness and decency are rare enough in the literary world to be disarming when married to real talent. But when it doesn’t — well, then you end up with Away We Go, a slight travelogue co-scripted by Eggers and his wife, Vendela Vida, and a movie that deserves every bit of snark that the critics of the world can hurl in its direction.

Our heroes are Burt (John Krasinski) and Verona (Maya Rudolph), an early-thirtysomething couple who embody the Eggersian virtues: They’re talented without being too ambitious, humorous but non-sarcastic, and devoted to each other without being sentimental about it. They’re also expecting a baby, a blessed event that sends them on a jaunt around North America in search of the best place to give their tyke the wonderful childhood he deserves.

The trouble is that most of the potential landing places are filled with people who aren’t nearly as nice as they are — starting with Burt’s parents (Jeff Daniels and Catherine O’Hara), who blithely announce that they’re moving to Belgium two months before their first grandchild is due. Why Belgium? Who knows — and who cares. The point is that they’re awful people — grinning, self-absorbed fools — and the audience is expected to laugh at their awfulness, sympathize with Burt and Verona, and feel righteously appalled that their unborn child will be forced to share an extended family with such jerks.

The same pattern plays itself out in Phoenix and Madison, Wis., the first two stops on their round-the-continent tour. In Arizona, we meet Verona’s former office-mate (Allison Janney), a profane lush who berates her paranoiac husband and overfed kids amid strip-mall parking lots and greyhound races. Then it’s off to Wisconsin, for a horrific evening with Burt’s childhood friend LN (Maggie Gyllenhaal), a self-righteous earth-mother academic who murmurs about “continuum parenting” and rages against strollers.

The movie turns down the satire for its final vignettes, featuring an infertile Montreal couple and Burt’s Floridian brother, recently abandoned by his wife. But by then the tone has been set. Away We Go proves that niceness, taken as a principle, can run to intolerance as quickly as any other. The script doesn’t care why people don’t live up to the standards of its protagonists. (There’s no attempt, for instance, to explain why Burt’s brother’s wife might have fled their seemingly happy home: She wasn’t nice, and this is all ye know and all ye need to know.) It just wants to mock, deplore, and caricature them. This is a movie with the soul of a “mean people suck” bumper sticker.

Away We Go was directed by Sam Mendes, which at first feels like a mistake. Mendes, a Brit with a zeal for suburb-bashing, does glossy, self-satisfied dramas with big-time movie stars, not scruffy, self-satisfied little comedies with “where do I know her from?” actresses in important roles. Were the people who made Little Miss Sunshine unavailable?

But in fact Mendes is the perfect choice. Eggers and his wife hate mean people; Mendes, on the evidence of American Beauty and Revolutionary Road, just hates America. And while this is a smaller film than he’s used to making, it provides a wider canvas for his prejudices. There are nasty Americans beyond the confines of suburbia, it turns out, and Mendes is just the guy to show them to us. Grossness, self-righteousness, and self-absorption abound just about everywhere — from the mountains to the prairies to the oceans white with foam.

Well, maybe not the oceans, since that’s where Burt and Verona end up — in a deserted house at the end of a deserted road, with doors that open onto an empty, windswept bay. It’s supposed to be a happy ending, but really it’s the perfect conclusion for a movie that occupies the place where niceness curdles into misanthropy. When you can’t find anyone nice enough to share your life with you, you end up without anyone at all.