Just kidding.
But seriously, you would be surprised at how derivative these books really are.
What books do you think Rowling's are derivative of? She acknowledges her debt to classical lit (using British sense of classical, as in Roman classics) and I can't say I see HP as being directly drawn from any modern sources. Sure, the ideals are all there, if we're talking Campbellian archtypes.
I wish; Rowlings' publicist is making a lot more money than I currently am.
So was Shakespeare -- and practically everyone else. It's only in modern times that that became a "flaw" -- well, "modern" from the 18th century or so. (See The Battle of the Books.)