Things that don't exist don't matter.
After filming of the first three Star Wars films, Lucas went to extreme measures to try and keep details about the story from being leaked — even going so far as sequestering cast and crew, etc. After filming his parts of Phantom Menace, Liam Neeson went on Letterman's show and when asked about the story, said he didn't know what it was even about. He worked primarily on a green screen and had no idea what would be on the screen with him. Broadly speaking, that is what makes CGI suck.
Willem Dafoe was on the Colbert Report promoting John Carter last week. Watch for his severe lack of enthusiasm.
CGI empowers lazy directors. Frank Miller's Spirit movie. Watch the making of featurette for Beowulf to see the flabby thing Robert Zemeckis has become.
"The trouble with being a ghost writer or artist is that you must remain anonymous without credit.
If one wants the credit, one has to cease being a ghost and become a leader or innovator." — Bob Kane