I bolded part of the article because that seems to be the primary argument of the posters defending the potter books.
The other pro-potter argument seems to be name calling or portraying those that object to the potter books as nuts, which is really no argument at all. It reflects an old adage. When the facts are on your side argue the facts. When the facts are against you, attack the person.
When choosing some feature of popular culture to criticize, I suggest the social conservative move and speak with caution. It is too easy to be portrayed as a petulent crank. Save your energy for better battles, like the garbage that is on our nightly sitcoms.
Keep your perspective, if you would strive to have an inflence on the culture. The Potter books surely do have some accoutrements of the occult, but so do the Arthurian legends and most of science fiction and fantasy. Fairy tales wouldn't be much fun without magic, spells, witches, etc. There are several "appoved" books I read as a child about child-witches being apprenticed by other witches, but no book so commercially popular as the Potter books.
As a former reading teacher, I can attest to the value of a child keeping his eyeballs moving across the words of a page. This increases reading fluidity and skill, even when the quality of what he is reading is negligible. I understand how heartened librarians can be when a series of books, books with challenging vocabulary, becomes popular to children.
In sum, don't waste your resources on the Potter series.