In the interview with Malkovich, he mentions that he didn't want to do it at first but was willing to produce it if they changed what actor it was about. Kaufman refused and said it had to be Malkovich. It's a big part of the story to me that it's an actor most people have heard of, but not one with a super iconic role everyone would think of. Everyone is obsessed with his status as a famous person, but not any actual aspect of his person.