http://killscreendaily.com/articles/interviews/assassins-creed-iv-lead-w...
When you hear his idea for the "perfect Assassin's Creed game"
you may understand why some portions of AC3 were what they were.
Oh, and this video is amazing on so many levels: http://www.youtube.com/watch?v=i22dh6fIjwM
*slinks away into shadows*
Pretty interesting video and article regarding how story-telling in video-games differ from TV, novels, music, films, or plays.
In other words, gameplay has to compliment story, and vice versa.