Not that he cares, of course. But the bestselling author does a major disservice to science and history that just isn't necessary.
I certainly don't begrudge Brown his commercial success. He's found a winning formula and is no doubt having a great time with it. But why would you insist the background information in your novels was real when it wasn't?
Millions of people who read Angels and Demons or watched the film no doubt believe the Catholic church murdered and branded four scientists and dumped their bodies in Rome as a warning to others. People who read the novel will think Christian fundamentalists killed the Superconducting Super Collider project, when that had absolutely nothing to do with it. (It was killed by a Congress unable to see the value in a project that wouldn't yield immediate, quantifiable benefits.) And don't get me started on the inaccurate physics.
It would not hurt Brown's reputation or success one bit to back off his statements that some of the most dramatic stuff in his novels is real.