The tone of "Rip Van Winkle" is serious and scholarly on the surface, but ultimately it is lighthearted and comedic, mocking traditional heroes and history. Rip becomes a folk hero by accident, not because he does anything particularly heroic:
Having nothing to do at home, and being arrived at that happy age when a man can be idle with impunity, he took his place once more on the bench at the inn door and was reverenced as one of the patriarchs of the village, and a chronicle of the old times “before the war.”
Rip "chronicles" the pre-Revolutionary period, keeping the villagers connected to the memory of who they were before the Revolution completely changed the way they think of themselves and their neighbors. Beneath the passage's praise of Rip as an important keeper of history, it pokes fun at him as a terrible war hero: passively resisting his wife's urges to work for a living, he simply waits out his life until laziness becomes age-appropriate.
The story does not necessarily take issue with Rip's anti-heroism. The mock-seriousness rather raises the question of whether readers take the American Revolution and the straightforward war hero (like George Washington) too seriously. Diedrich Knickerbocker thinks very hard about the best way to collect and narrate the important bits of history:
The following Tale was found among the papers of the late Diedrich Knickerbocker...His historical researches...did not lie so much among books as among men, for the former are lamentably scanty on his favorite topics, whereas he found the old burghers, and still more their wives, rich in that legendary lore so invaluable to true history.
This passage pokes fun at traditional historians' professed obsession with getting the facts right. Early readers knew that Knickerbocker and his silly name were fictional inventions by Irving, so to listen to him was already to throw "facts" out the window. But Knickerbocker sounds so legitimate. The passage boosts its credibility by using authoritative language to defend Knickerbocker's reliance on oral narratives. Any historian could do the same to sound trustworthy. Beneath that authoritative tone is buried a claim that Knickerbocker was as much gossip columnist as scholar. Maybe this makes him untrustworthy. But maybe, the story lightheartedly suggests, those who want to preserve culture should take big historical events like the Revolution less seriously and instead listen to more silly gossip. After all, the villagers continue to tell stories about each other after the Revolution, and Rip continues to be as lazy as ever. Overemphasizing how much the Revolution and George Washington changed the world, the tone suggests, erases these small figures at the heart of American life.