Fantasy may have the most rabid and obsessive fans, but it also has the staunchest detractors of any mainstream genre. We all know people who simply refuse to watch fantasy films or read fantasy books of their own volition. They may have sat through The Fellowship of the Ring grudgingly, but didn't bother with the rest of the series. They probably associate the genre with asocial nerds, fan conventions, and Dungeons & Dragons. They can only shrug at the exuberance of the devotees. Fantasy is "not their thing."

Why are fantasy movies (and the genre in general) so polarizing? I've long thought it has something to do with viewers' relative affinity for cinematic worlds. Some people go to the movies to see something that directly relates to their own lives, something that takes place in the universe they live in and know. Others – myself among them, if you haven't figured it out – flip for new, self-contained worlds that could exist independently of the movie; wonderful and strange places we feel like it's possible to actually inhabit. This might explain why those who like good fantasy also tend to enjoy good science-fiction.

It also explains why Chris Weitz's adaptation of Philip Pullman's The Golden Compass – the first part of a magical trilogy called His Dark Materials – doesn't work. The novel's fantasy world is one of the most painstaking, unique and enchanting I've had the pleasure of visiting. It gives a nod to genre archetypes – the Chosen Child, the Coveted Magical Trinket – but after that it wanders off on its own: elemental "dust," parallel universes, "the Church" as a villain, talking polar bear royalty, and most memorably, a physical representation of the soul of every human being in the form of a different "daemon" animal. Pullman created a coherent, logical universe with its own rules and order – and the books became huge, lasting bestsellers. Rightfully so.

How, then, did last year's Weitz adaptation come to look and feel like every kiddie fantasy movie Hollywood has ever made? Why do the characters seem to inhabit not a different world, but a plastic Hollywood soundstage? Why are the daemons such harmless, nondescript CGI beasties – talking stuffed animals – instead of integral characters with their own personalities and as much emotional pull as the human protagonists? Why is Nicole Kidman's version of Ms. Coulter such an ordinary conniving villainess instead of the steely, fearsome, beguiling presence that she was on the page? The outlines of Pullman's story are here – but what happened to its heart?

Much was made of the fact that, in a bid to stave off opposition from religious groups, The Golden Compass was scrubbed clean of any reference to "the Church," and the truth-suppressing bad guys were referred to solely as "the Magisterium" (a word that did also occasionally appear in the books). It was an artistically disgraceful move, turning a frightening, monolithic, nearly omnipotent villain into a bunch of mean-looking old people conferencing in a darkened room. But it was a symptom rather than the disease.

The problem is bigger than the religious angle: the entire movie feels sterilized, robbed of any shred of distinctiveness. The novel has some genuinely wrenching moments once Lyra discovers Ms. Coulter's nefarious plan to separate children from their daemons, culminating in the tragic death of her best friend Roger – but all of them are either blips on the radar in the film or gone altogether. The strange beauty of Pullman's imagery is replaced by gleaming, generic CGI deployed without imagination. There's no world to enter here – just the realm of expensive, Disney-fied blockbusters. This even though Disney had nothing to do with The Golden Compass.

The movie was meant to kick off a new franchise for the now-defunct New Line, something that might replicate the success of The Lord of the Rings. The Golden Compass' box office performance was tepid, at least in the US, and so the fate of the sequel (The Subtle Knife) is unclear. As far as I'm concerned, it's just as well. I love fantasy because the best of it – like Phillip Pullman's novels -- takes me somewhere new, and shows me things I've never seen. Except for parts of the third act, the movie is faithful to Pullman's plot, but not to the novel, not in any way that matters. It puts the story on the screen, but in the process turns it harmless, boring and blandly inoffensive -- presumably the better to sell it to a mass audience. And then it turned out they couldn't even do that. Bah humbug.

[For next week, I'm reading Nick & Norah's Infinite Playlist. The adaptation stars Michael Cera, plays Toronto in September and hits theaters in October.]