V For Vendetta induced a fair amount of walkouts on its opening week in the States. Not as many as, say, Irreversible, but the comparison is valid: just as Irreversible begins by encoding nausea-inducing extra-diegetic sound onto the first reel, so V For Vendetta opens by encoding into the background expository monologue the information that years of war and biological weaponry have turned America from the world's greatest superpower to its biggest leper colony. Apart from explaining to international audiences why we're watching a blockbuster made by Warners but containing nary an American accent nor location, it does little; but, by the sounds of it, the opening gambit serves its purpose as a piece of provocation.
It's on this level that V is most successful. As the blockbuster-with-brains political/philosophical Manifesto it wants to be, it's wooly and self-contradictory; as a Matrix-level action movie, it's a little too concerned with being a Matrix 2-level political/philosophical Manifesto. But as a big, brash, unsubtle bid for the title of Least Subversive Piece Of Subversion Ever, it's great fun.
Alan Moore, of course, has been pretty darn vocal in expressing his discontent that his allegory about Anarchy vs Fascism has been transplanted into a condemnation of Rightist politics from an unapologetically Leftist perspective. I can't help feeling there are worse things that could happen to your story - The League Of Extraordinary Gentlemen, for instance.
Sure, sure, I'm a big commie faggot pinko Jew, but while it's hard to call V an underground counterculture piece - neither Warners nor Joel Silver are known for their presence on the indie circuit - it's hard not to get caught up in V when it's on-message. Moore does have a point, though, in that the sermonizing gets to a point where the narrative has to pause for Steven Fry to remind us that even non-Muslims can admire the Koran's poetry, or for William Hurt to scream and yell so he can be sure that audiences, seeing a demagogue in a combover named Adam Sutler, don't miss the inference.
The trickest aspect of making a V For Vendetta movie, and the one in which the picture gets the most hamstrung, is that quiet underground cult comic books like very much to be about shades of grey, whereas Big Loud Action Movies like things clearcut and binary. And the Wachowskis, God bless 'em, have tried to make a movie which clearly and loudly and explosively encourages audiences not to think in polar absolutes.
So you have an eponymous protagonist who fights for good, but whose politics are so hinky you'd be hard-pressed to call him a hero; nemeses in the service of a corrupt fascist dictatorship, but a narrative that tries to quietly point out that Anarchy is also a somewhat embarrassingly unrealistic option. These are factors that work in the narrative's favour in the comic book, but in the movie, where so many things are reduced to simplicities, it makes the ambiguities confusing and uncertain.
This is most worrying in the climax, in a scene stripped straight from The Matrix, where a batch of Government grunts are dispatched brutally and remorselessly; but whereas The Matrix's equivalent sequence was preceded by a reminder that, in that movie's narrative, the forces of evil were inhuman tools of oppression, V For Vendetta immediately follows this scene with one in which the humanity of the Government soldiers becomes a point for celebration. That scene in The Matrix was always worrisome, but in the context of V For Vendetta, it's doubly unsettling.
And it might work if V the movie weren't so intent on portraying V the character as heroic. While the movie does great stuff positioning him as the unstoppable force of Anarchy to William Hurt's immovable Fascist object, it neglects the necessary nuances in which we're reminded that, actually, Anarchy is also a fairly hinky pipe-dream. His parting words to Evey still paraphrase Aliastar Crowley's most-repeated proclamation, but no longer does she reply by pointing out that that's a load of old tosh anyway. (Moore, elsewhere, makes clear just how seriously he takes that particular branch of philosophy; the Wachowskis, though obviously big Moore fans, don't follow through).
For a movie that wants so much to be all about big notions and messages, V works best when it's dealing on an individual level with things that don't need a big garbled monologue to be conveyed. The film's strongest sequence is one bereft of sledgehammer allegory or power-in-numbers pontificating, and it almost carries the narrative through the dodgy terrain that follows. Almost.