It is not the content that makes characters complex, but the arrangement of that content. We know people who have one-track minds or are so aligned to be predictable (and often, therefore, boring!) People who are more diverse contain conflicting or unlike traits and are much more interesting to be around. So it is with characters.

Imagine building characters to be like playing Scrabble. There are a given number of letter tiles, no more, no less. The object is to create words using all the tiles. The game won't feel complete if any unused tiles remain. Now imagine a set of words that are all the same length and use up all the letters so none are remaining. Suppose there is only one combination of letters that will do this. If we build characters that way, we get the one and only Archetypal set. There's nothing wrong with playing the game that way, but after a few zillion times, seeing the same limited set of words over and over wears thin. It is much more interesting to create a wide vocabulary of all kinds and sizes of words.

Archetypes Have Their Place, But....

Archetypal Characters have their place, mind you. If an author's focus is on Plot or Theme, he may want to create easily identifiable Archetypes as shorthand to save space and time. As soon as the edges of an Archetypal Character are sketched out, audiences (who have seen these Archetypes time and again) will fill in the rest, waiting for information to the contrary. In this way, an author can free up time or pages for aspects of the story that may be much more interesting to him.

As a result, Complex Characters are often the first things torn down to conserve media real estate. This leads to a glut of action-oriented stories populated by stick figure people. Whenever there is a glut in one place, you will find a shortage somewhere else. The imbalance between glut and shortage creates demand. Box office is directly proportional to demand. No more need be said.