Actually, I really like Dan Brown's writing style. It really draws you in and is really effective. The only problem is that Brown has only written one book, really. All his novels have the same, highly specific format. It's only the details that are different. The plot exposition, the characters etc are all mostly the same.
Lots of popular novel writers use formulaic writing, applying the same recipes again and again, and that seems to please their readers. Pretty much all Agatha Christie novels share the same basic plots (one character is killed, sleuth asks questions to everyone, finally everybody is in the same room of a castle / manor and sleuth gives the answer), with the same stock characters (rich people), for instance, and she is one of the biggest book sellers ever.
Perhaps he ascribes to the aphorism "if it ain't broke don't fix it". People keep buying it for better or worse, if he wants to break out and try alternate styles he's probably better to use a pseudonym. Sometimes you like to have an idea of what you're getting in to with a book, sometimes not.
