No, Whedon couldn't have made a better movie (but that's because Whedon is a wanker). I'm saying Whedon glommed onto this project because he thinks it's his ticket to becoming a top-level Hollywood player (and he may be right). Sort of like how Raimi jumped on Spider-Man, or Jackson on Lord of the Rings, except those two were only seeking validation as directors. Whedon wants to be a brand, like Cameron or Spielberg.
"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