The total message of the movie was faintly reminiscent of the themes of belief in The Santa Clause, though I think that film did a much better job on most counts, and it also delivered its moral more intelligently. Oz leaves the viewer with the impression, not quite of an end-justifies-the-means mindset, but of an "It came out all right, so we must have done the right thing!" mindset. The former would seem to be the cynical incarnation, the latter its naive counterpart.
This isn't at all unique to that film, or to art in general; it is a (though certainly not the) motive force in our culture -- a sort of pragmatically retrospective optimism. It is a close parody of a number of more creditable attitudes (such as making the best of an admittedly unjust or unsatisfying situation), and is one of the flowerings of the pragmatic element of the American psyche -- the worship of success.
Whether in its naive or its cynical forms, I take success-worship to be essentially opposed, not only to Christianity, but to common sense and human happiness. That cynics are not happy, and that naive optimists are not sensible, seems like a truism. Really both parties are neither. The cynic, who reduces everyone else's motives to either stupidity or self-interest, is just as unintelligent as the naive optimist -- indeed, he is often an optimist who has been soured -- the thing that has changed is the direction in which he oversimplifies, not whether he does so. And the naive optimist may seem happy; but is he? Naivete (not to be confused with purity of heart) is always the result either of immaturity or of stunted growth. Any growth as a human being will come at the cost of that naivete, though not necessarily at the cost of his goodness: the only way to remain naive is by deliberately resisting that growth, and -- "We cannot go on being ordinary, decent eggs. We must be hatched or go bad."*
I rather think that this is one of the things that makes the virtues so hard. We have been sufficiently affected by the surrounding culture that we import its success-worship into our view of growth and holiness. Take fasting. I have been a Christian for as long as I can remember (with one exception that need not detain us now), and yet it is really only within the last year or so that I have begun to practice fasting with anything resembling regularity. Why? Because it's so hard -- so hard that I thought, surely, if God wanted me to fast, it would be easier. Surely doing the right thing would come with -- not instant gratification in the vulgar sense, but at any rate instant interior gratification, instant assurance of rightness and consolation and all of that. Surely it would work!
But of course that isn't how reality is. Donald Miller, in one of his books (Searching For God Knows What, I think), recounts a friend saying to him, "Reality is like a fine wine. It will not appeal to children." An adult spirituality, suited to a corrected palate, is the desideratum: and an adult palate knows not only the milk and the honey of the promised land, but the myrrh and the vinegar of Golgotha. And that does not only indicate repeated hardships, but repeated failures on our part, something I have been grappling with in great anguish over the last two or three years. The choice between settling for the quite livable compromise of mere social decency, and being bad at an attempt at real holiness, is a humiliating one: in either case, you must make peace with a kind of inferiority in yourself -- either you know that you have deliberately refused a greater glory, because it is too shaming to be continually confronted with the ways in which you fall short of it; or you embrace that continual confrontation, and feel the repeated sting of being so far beneath the heroism you aspire to. Either you must know that your heart is too small for a great ambition, or your powers are too small for a great heart. For years, much though I love the saint, I bitterly hated St. Teresa's maxim, but I am starting to grasp it more of late -- here, so applicable: "You must learn to bear for God's sake the trial of being displeasing to yourself."
*C. S. Lewis, from Mere Christianity.