Rip Van Winkle himself is described as being rather lazy; he doesn't like to commit himself to manual labor and so allows his household to become disorganized and decrepit. He prefers to wander the woods in the manner of a hermit, and his wife is understandably irritated with his lack of work ethic. Interestingly, his only voluntary act of charity in the form of labor -- helping carry the ale up the mountain -- results in his being removed from the waking Earth for twenty years. Upon returning to civilization and discovering what has happened, Rip is subtly joyous, as he now has no responsibility to work and no wife to nag him.
Having nothing to do at home, and being arrived at that happy age when a man can do nothing 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."
(Irving, "Rip Van Winkle," bartlby.com)
The moral of the story, then, is oddly opposed to a strong work ethic. Most of the people that Rip knew in his youth are dead, either from the stresses of everyday labor or from participating in the Revolutionary War; Rip avoided both simply by sleeping through them. Although likely unintentional, if a moral could be ascribed to this story, it might be that it is better to avoid hard work because there will be a coincidental happy ending later. In the real world, this type of outcome is almost never true.