I don't see Mr. and Mrs. Smith on the screen. I see Brad Pitt and Angelina Jolie acting roles that pale in comparison to the ones they allegedly played in real life at the time of filming. Talk about spoilers...
Something similar happens for me when a novelist becomes an overexposed celebrity. Once the persona of the author takes precedence, her characters and stories become less convincing. I don't see the characters living their roles; I see the author creating these characters and putting them through their paces. That is not a minor distinction; for me, and for many readers, I imagine, this difference in perception is nothing short of disastrous. The suspension of disbelief that's so necessary if the reader is to be absorbed into the world of the story just can't happen.
I'm not talking here about the normal details that make up an author's bio, his occasional observations about writing or living the writer's life, but rather the up-to-the-minute, voyeuristic bombardment with tedious details of his private life, his opinion on subjects unrelated to his work, his daily routine, his children, pets, vacations, shopping sprees, peeves, diet... If it ties in with his work in some way I'm fascinated. Anything more and I'm turned off. I often long for the bad old days when all I knew about my favourite authors was what I read in brief biographies on jacket flaps. I knew them through their work, and that was all I needed.
Sad to say, there are authors out there, probably good ones too, whose work I avoid because of their overexposed-celebrity status. Dan Brown is one. I didn't pick up a Steven King book for many years for the same reason. Don't stone me, but JK Rowling is another.
Suspension of disbelief is critical for my enjoyment of fiction. How does an author's celebrity status affect your appreciation of his or her stories?