Board Thread:General Discussion/@comment-3392084-20130707145759/@comment-6747658-20130707155023

Or...like Kojima himself said, he wanted an actor who could portrait the character through more then just voice but through facial expressions as well. Kiefer is far better in facial emotion then David is (if you ever saw Guyver: Dark Hero you'll see why) Hayter is just a voice actor, he most likely wouldn't be able to create that facial expression that tells the emotions without voicing them, something Kiefer can do.