To Read or Not To Read?

My favorite living writer, Umberto Eco (of The Name of the Rose and Foucault's Pendulum), was once asked why he thought the Harry Potter books had done "so well". The question was framed in a snide manner, implying that we had somehow reached Wells' Time Machine end and we'd all become too stupid to function, hence, adults reading children's books.
Without blinking, he answered that, like Homer and like the Brothers Grim, Harry Potter served an eternal function in our society as fantasy has done for countless societies the world over. The upstart student, appropriately shut up for the remainder of the lecture, made me question my own prejudices. Many of my friends and relatives thrive on, what I think of as, "young adult" or "teen lit" books which I have often turned up my nose at.
With the advent of the sixth Harry Potter movie arriving in theaters this summer, I thought I'd take Eco's cue and pick up the series. Under the guise that I was reading them to Kai for a bedtime story, I allowed myself to fully enjoy them without embarrassment. Now on to the third book, after a week of reading, it is clear that I am reading far past my son closing his eyes.
Far from intricate, the prose is straightforward and simple, but runs along at a clip that would make any of my "normal" reading dizzy. There is merit to reading Pynchon and Sartre, of course, and they should be encouraged in schools far more often than they are, but we often downplay the significance of purely imaginative, playful make believe in the education of our children and ourselves.
Am I simply defending my recent foray into the dark arts and flying broomsticks by constructing a more palatable place for them in literature? Perhaps. I'd like to think, though, that children and adults alike, ate up Homer and Shakespeare's tales of sirens and donkey head, respectively of course, as much as they latch on now to Harry Potter and, yes, I'll admit, Edward Cullen.
For the moment, I'm content with my conclusion. Fantasy is literature in its own right. what do you think? Yes? No? Maybe? Is reading anything better than reading nothing at all?