Yes, I think you've hit it. Ratzinger rejects this particular fantasy world....probably because it's too close to an occult world.
I've stayed away from this topic recently (but I always appreciate getting pinged to it) because those who read these books seem to enjoy them so much and get so ornery when anyone challenges their pleasure.
I can understand that. I still enjoy Halloween.
But IMO an accurate understanding of the Harry Potter books can be reached only by understanding the Theosophical roots that permeate every page of these books.
Even the term "Harry Potter" was once a colloquialism for the Devil himself. The books are filled with occultic terms and scenarios.
Vlabatsky/Blavatsky
When one understands the roots of Theosophy and its many incarnations past and present, you can't help but realize you're being subliminally swayed to be positively conditioned to its influence.
What child who's read HP will read the name Helen Blavatsky at some future date and not be quite as repulsed as he should be by the name of this anti-Christian occultist?
Indeed, that's the very point of these books.
And just as surely as water flows downhill, making ever-larger mud puddles, the next edition of HP gives up the game completely just by its title -- "Half-Blood Brother".
Like all occultists/theosophists/universalists the key to the boy Harry Potter's strength lies IN HIS BLOOD.
Where have we heard that one before? From the organization that used as its symbol the same "Lightning Bolt" that Harry Potter proudly displays on his forehead.
Two internet sites which were the first-up on google clearly explain the massive subtext to these "children's" books.
Harry Potter and the AntiChrist
and
As Martin Luther warned: "The devil plagues and torments us in the place where we are most tender and weak. In Paradise, he fell not upon Adam, but upon Eve."
So then our responsibility is to protect our most precious earthly gifts, our children, from whatever forces seek to mislead, misinform and ultimately destroy them.
Train up a child in the way he should go: and when he is old, he will not depart from it." -- Proverbs 22:6