In order to counter the unreality of Ibsen and the bleakness of Chekhov, John M. Synge has chosen a seemingly unbelievable story to create his realist masterpiece, The Playboy of the Western World. Its realism comes from two unlikely sources: joy and a far-fetched tale. Yet, as Synge identifies himself in the preface, these elements in combination are extremely effective in showing the life of the peasantry; more so than any bleak or so-called "real" story (in the manner of Ibsen) could.
The problem with showing the peasant class in a bleak manner is that, by virtue of their position, the audience knows their life is bleak in terms of money. By featuring a peasant class, it would be redundant to make a movie about their lack of finances, intelligence, or other virtues not usually associated with a so-called "lower" class. So in the same way that Ibsen shows us that the upper classes have troubles with life, Synge shows us that the peasant class loves life to its fullest through their zest for life.
On the surface, it may seem like ridiculing to talk about going to wakes and vomiting all over the coffins, or to have a killer as a good "guard" for a daughter; but it is only in this way that Synge can bring the texture and true joy that lives in the peasants to all audiences. There is true joy in almost everyone's actions, from the happiness at discovering a good story in the boy who has killed his father, to the cheering of the easily-changed crowd against Christy Mahon in the end. It is clear that these peasants live life to the fullest in a sort of hedonistic manner. Their main concerns are not money or fame, but having the best possible time with the present, and there is a definite appeal to this type of behavior which can draw any audience member into the story.
But the happiness alone does not make The Playboy of the Western World. The fantasy of the tale keeps the story from being one of only hedonism - which, in itself, must always lead to ruin in a "realistic" play by the moral conventions that surround society - and makes it something much more.