Stewart said:
No wonder you didn't like it. A quick google search reveals that a lot of people aren't talking about the plot. They are talking about whether Dan Brown's so called "meticulously researched facts" are actually factual.
http://www.opusdei.org/art.php?w=32&p=7017
http://www.catholiceducation.org/articles/persecution/pch0076.html
http://www.catholic.com/library/cracking_da_vinci_code.asp
Why should a Catholic be concerned about the novel?
Although a work of fiction, the book claims to be meticulously researched, and it goes to great lengths to convey the impression that it is based on fact. It even has a "fact" page at the front of the book underscoring the claim of factuality for particular ideas within the book. As a result, many readers-both Catholic and non-Catholic-are taking the book's ideas seriously.
The problem is that many of the ideas that the book promotes are anything but fact, and they go directly to the heart of the Catholic faith. For example, the book promotes these ideas:
Jesus is not God; he was only a man.
Jesus was married to Mary Magdalene.
She is to be worshiped as a goddess.
Jesus got her pregnant, and the two had a daughter.
That daughter gave rise to a prominent family line that is still present in Europe today.
The Bible was put together by a pagan Roman emperor.
Jesus was viewed as a man and not as God until the fourth century, when he was deified by the emperor Constantine.
The Gospels have been edited to support the claims of later Christians.
In the original Gospels, Mary Magdalene rather than Peter was directed to establish the Church.
There is a secret society known as the Priory of Sion that still worships Mary Magdalene as a goddess and is trying to keep the truth alive.
The Catholic Church is aware of all this and has been fighting for centuries to keep it suppressed. It often has committed murder to do so.
The Catholic Church is willing to and often has assassinated the descendents of Christ to keep his bloodline from growing.
My dictionary gives several defintions of theme, but one is "a distinct, recurring, and unifying quality or idea:"
Plot is defined as: "The pattern of events or main story in a narrative or drama"
"The humanity of Christ," is an distinct idea that reocurrs throughout the Da Vinci Code. It's not an event in the narrative. Sounds like a theme to me.
But to stay on topic. Everything about a book matters: genre, cover, sales, publicity, reputation of the writer etc. Different people react differently to all of those things. Which is one of the reason books are pretty cool, and discussing books is so interesting.