teleny's excellent article above deals with the enormous stylistic, factual and religious problems with the novel, and I would urge you to read the write-up rather than attempt a clumsy rehash. I would however like to highlight an additional problem, not artistic but purely ethical, that also arises from the success of the book: most of the central themes are based on misinformation and outright lies. And I don't just mean Brown's schoolboy errors about this or that art work or this or that church, nor the deliberate re-writings of facts that he uses in order to make an uneducated audience comfortable in a pseudo-learned fictional world.
Brown freely and maliciously libels Opus Dei and the Catholic establishment as murderous, cynical and in every other way evil and controlling of their flock. Now, one accepts that every detective romp with conspiracy undertones needs a properly sinister and villainous bunch of conspirators, and it’s much easier to borrow rather than to invent them, which is why so many novels are written about FBI conspiracies, mafia conspiracies, big pharma conspiracies etc. Still, there is a line between the entertainingly mischievous and the outright libellous, and in my view (as well as that of millions of Christians, whose faith is the subject of Brown’s attacks) that line is crossed here. This would be my final argument to the usual “oh, but it’s only fiction and it’s such a good read” defence of the novel: if you replace “Catholics” with “Jews” or “The Divine Feminine” with “Sex with Children”, is it still great entertainment?
Ultimately though, there is a problem with discussing The Da Vinci Code at all, and that is that there are so many and diverse reasons that it is a bad book. On almost every level of examination, from the purely artistic to the entirely mundane, it fails so dramatically that one is almost embarrassed to expound what should be obvious to every reasonably thoughtful person. Of course the difficulty is that it’s not obvious at all, and that in attempting to explain them one is often accused of either elitism or simply falsehood.
I believe that the challenge of supporting the critical view of the book in conversation is closely linked to the complexity of the arguments in its detriment. In fact, there are as many reasons to hate this book as there were to go to war in Iraq; unfortunately, the latter were all either morally repugnant or simply fictitious, and funnily enough that seems to be a major stumbling block when attempting to discuss the book in a non-academic environment. People are just suspicious of anything that has too detailed a reasoning behind it. That the book's success occurred after the breakdown in confidence between Western readers and their governments, and during a period of gross conspiratorial paranoia is, in fact, revealing.
A healthy scepticism of information provided by power or intellectual elites is of course a good thing; however the phenomenon that is TDVC can almost be ascribed to a violent public reaction to what they see as an attempt to manipulate their tastes from above, by either the literary establishment, the Catholic church or the art historian fraternity, all of which are viewed more or less with suspicion by the average outsider anyway. And in the absence of a single, accessible, non-academic and non-technical argument, one that creates the same conditions of fake self-esteem in the reader, in fact, as the novel does, that debate, for now, remains unwinnable for the side of the critics.