I'm not even on the scale of fandom for Harry Potter reading/watching*, but I do appreciate a good defence in the face of criticism (even though a large proportion of readers here appear to have spent most of the last few days buried in book 7 themselves so probably not many critics here...).
Anyway, it's with great delight I point you to Clare and her spirited protection of escapist reading.
As I have said before, I liked 'The Da Vinci Code' because it was a page-turning bit of fun. I like the Harry Potters' for the same reason. I don't need - let alone want - all my reading to be serious or 'good literature' (whatever the hell that is). I have spent - and still spend - vast amounts of time reading quite dense texts. I like doing that and some of the stuff I read for pleasure would possibly baffle some folk. Nevertheless, I also like to coast through some books and that's where certain fiction comes in.
Having said this though, it seems only fair to point out that even if the Dan Browns and JK Rowlings of the world can be acknowledged as not demonstrating the pinnacles of western literature, that is not to say that they do not present worthwhile ideas. To take the Potters, we get the tracking of growing up, the death of family and loved ones, betrayals, learning emotions from experiences, education... and all wrapped in a magical bag of spells, werewolves, battles of good and evil and the power of love. Awh. What's not to like?
* yes, yes, I know I have watched the GoF several times. Shoot me.