The Great and Powerful Plot and its role in "Character Books"

I must start by confessing that I'm a plot addict. I'm not one of those lucky people who can write without an outline. My first manuscripts had very clear good guys trying to get something good and very clear bad guys trying to thwart them. For a long time, that was the way plot operated in my mind. You know...Frodo wants to destroy the One Ring—Sauron wants to use the Ring to dominate the world; Luke wants to become a Jedi Knight—the Emperor wants to use Luke's power to...um...dominate the world. Even more ambiguous plotlines, like...Harry wants a family and friends and love—Voldemort wants to rid the world of things family and friends and love (and dominate the world)...were ok, because there was still a flesh-and-blood bad guy that Harry had to fight in order to get what he wanted.
But recently an idea took seed in my mind that I couldn't get rid of. (Pesky idea weeds...) It was for...gulp...a “character book”. I've always loved character books, but for the life of me, no matter how many I read and how much I read about them, I could never fully grasp how they worked. Or rather, why they worked. Where were the Saurons and Darth Vaders? Who was the bad guy?
Finally after weeks of scratching out outlines and charts and lists—and reading lots of wonderful character books and eating several bars of chocolate—I had an epiphany.
(Note: please don't laugh at me if everyone in the world knows this already. Maybe it was something I just had to discover for myself...)
There is a bad guy in every character book. It might not be flesh-and-blood, but it is real and scary and nearly tangible. It is the character's Greatest Fear.
Here's what one of my figuring-this-out charts looked like as an example:

Who/What is the bad guy in Because of Winn-Dixie?
     Well...who does Opal think is the bad guy? Who is she afraid of?
          She's afraid of losing her dog.
          She needs his help to make friends...is she afraid of losing them, too?
          She struggles every day with her mother's abandonment.
          She shares the pain of her friends who have touched death and loneliness and loss.
               So...the bad guy, the thing Opal needs to fight is...Loss. With a capital L.
                    Opal “wins” when she overcomes her fear of Loss.

I asked the same questions for as many middle grade character books as I could think of, and while the answers were varied, in every case the main character's greatest fear served as the plot equivalent of the evil villain. Anne Shirley in Anne of Green Gables has to fight Rejection. Damien in Millions has to fight Death. Claudia in From the Mixed-Up Files (etc....) has to fight Being Average and Overlooked. Millicent in Millicent Min, Girl Genius has to fight Being Better than Average and Overlooked.
Just like in a bona fide “plot book” these villains have their sidekicks. There are other fears to be overcome, until each story becomes a melting pot of obstacles to overcome—and maybe that's why the real bad guy can be so hard to identify. I guess if a writer didn't make the fight subtle, it would just be a poorly-crafted issue book.
So finally (finally!) I could fill out my outline and get ready to write a story. In the meantime, I'm fighting my own bad guy: Fear of Getting Up at Ungodly Hours so I can actually get pages written...