Very interesting stuff… I happen to have enjoyed reading the series thus far. I don’t think any adult would classify it as great literature. The plots are simplistic, the dialogue is so-so, etc. But in the past year, just for fun, I’ve picked up a few books by popular authors for “adults”, like John Grisham, Tami Hoag, and Iris Johansen, and what I found were books with simplistic plots, cheesy dialogue, and about a 4th grade writing level. I’ve also recently read a number of novels by Robert Ludlum… the plots and the writing aren’t quite as simplistic, but still lots of clunky dialogue, repetitive plotting, and the like. I think similar criticisms can be made of other popular authors that write for an “adult” audience, like James Patterson, Tom Clancy, and Michael Crichton. None of this stuff is great literature.
After reading a few pulpy books like that, I recently picked up “Heart of Darkness” by Joseph Conrad, and it really is amazing what a difference good writing makes. I could read a 500-page John Grisham novel in 6 hours, whereas it’s taking me much longer to go through “Heart of Darkness” (which is maybe 100 pages), because the writing is more complex, and there’s a lot more to read between the lines. But I can certainly appreciate a desire for both quick plot-driven page turners, and something that is more intellectually stimulating.
I also recently read “The Lord of the Rings” trilogy… I know critics debate the literary merits of this one, but it is definitely closer to being “literature” than is Harry Potter. I found Tolkien’s prose to be quite nice, with great use of imagery and descriptive language. There’s also more there on a symbolic level than you would find in Harry Potter or other contemporary pulp fiction. I think as a kid I would have found it tedious, but as an adult I really enjoyed it.