Ebert saw the film as a brutal satire of the American Dream. The "good guys" are the ones who refuse to grow up. The "villain" (Scott’s Derek) is a successful, sleek, Prius-driving entrepreneur who uses therapy-speak as a weapon ("The only thing that's going to be stretched is someone's face... across someone's fist"). Ebert noted, with a critic’s glee, that Derek’s comeuppance—getting punched in the face, losing his job, having his car vandalized—is presented as a moral victory. In Ebert’s reading, Step Brothers argues that success is overrated. Loyalty to your fellow chaos-gremlin is what matters. Roger Ebert died in 2013. In the years since, Step Brothers has undergone a seismic critical reappraisal. It is now frequently listed among the greatest comedies of the 21st century. Quotes from it have become linguistic shorthand ("Boats 'n Hoes," "Did we just become best friends?"). It is a cultural touchstone for a generation that came of age during the Great Recession—a generation that looked at the promise of adult life (careers, mortgages, 401ks) and decided, perhaps ironically, perhaps not, that building a bunk bed was a more worthwhile pursuit.

Ebert understood that Ferrell and Reilly were performing a kind of high-wire act. To play this stupid, you have to be incredibly smart. Reilly, an Oscar-nominated dramatic actor, and Ferrell, a sketch comedy savant, commit to the roles with the seriousness of Hamlet. They never wink at the camera. They never ask for pity. They are monsters of sincerity. Ebert once wrote, "Comedy is about pain, and the funniest people are the ones who are in the most agony." The agony of Step Brothers is the quiet horror of being forty and having no control over your own life. The comedy is the decision to burn it all down. To appreciate the radical nature of Ebert’s defense, one must recall the cultural context of 2008. The "Frat Pack" era (Ferrell, Owen Wilson, Vince Vaughn, Ben Stiller) was beginning to show wear. Semi-Pro had flopped earlier that year. Audiences were getting tired of the formula. Step Brothers opened to a modest box office, trailing behind The Dark Knight .

In the sprawling, chaotic archive of film criticism, few figures cast a longer shadow than Roger Ebert. For decades, he was the avuncular, thumbs-up oracle from the balcony, a man who could dissect the moral philosophy of Ingmar Bergman in one paragraph and defend the visceral craft of a Schwarzenegger action flick in the next. He possessed a rare gift: the ability to judge a film not for what it wasn't, but for what it intended to be.

Roger Ebert gave it three and a half stars out of four.

A lesser critic would have stopped there. Ebert did not. He recognized that the film’s stupidity was not a bug, but a feature—a deliberate, almost surgical, excising of adult social convention. Ebert wrote, "The movie is not about immaturity, but about the liberation of being completely, authentically yourself."