Take 100 random people who has not read the book, but have seen the movie. Pay each of them to write a novelization of the movie. Take the best 5 "novelizations", and I bet the original will circle around them, with the eyes closed.
Repeat the above experiment, but substitute random people with random English literature mayors. Maybe the average "novelizations" will have fewer grammar errors than the top 5 of the previous experiment... but over all, I still expect the original to be better written than the top 5 of the second experiment.
The guy had a good idea, and executed it well enough to make a success out of it. Get over it!
Dan Brown, just to go with our example, is a terrible terrible writer, by just about every imaginable standard of good writing. Dan Brown is a bad writer with a following. Nobody will remember who Dan Brown was 50 or 100 years from now.
Dan Brown is also a tremendously successful writer and you seem to have great difficulty believing, just like the original poster, that a bad writer can be tremendously successful. You also seem to believe that there is some inherent dichotomy between Dan Brown's success and his lack of writing skill. There isn't. That's my entire point.
Dan Brown is a dreadful, highly successful author. There is nothing logically or morally wrong with that. There's no reason there should be. He's simply an excellent counterpoint to the strange notion that bad writers cannot be successful.
P.S. Just for the sake of completeness, it's English majors, not mayors.
Are you so sure about that? Let's take the most popular mass-writers from the 18th or 19th century and see if they're remembered now:
18th century (US): Susanna Rowson / "Charlotte: A Tale of Truth" - doesn't ring a bell for me, and has a very small Google Search result (60.000)
19th century (US): Harriet Beecher Stowe / "Uncle Tom's Cabin" - I think everyone has heard of it :) and it has 15 times as many results as Susanna Rowson (Dan Brown has 17 times as many as Beecher Stowe, fittingly)
I personally at least recognize most of the bestsellers from the 19th century - probably Arthur Conan Doyle's books or Alexandre Dumas could have been seen to be as bad as Dan Brown in their time (I'm not arguing that they are)
20th century: Agatha Christie - still widely read as I recall.
sources: http://en.wikipedia.org/wiki/American_literature , http://en.wikipedia.org/wiki/List_of_best-selling_fiction_au... , and related Wiki articles, and googling
The Da Vinci Code is so poorly written, it's spawned a minor cottage industry of amusing commentary about how poorly it is written. A good place to start is here:
http://itre.cis.upenn.edu/~myl/languagelog/archives/000844.h...
[heh, I wonder what refined consumer of English literature and fan of Dan Brown was so upset by this so as to downvote it]