The problem with book Aragorn is that, although he has a story, and we get to hear about it, LOTR isn't his story, it's Frodo and Sam's. The part of his story that we DO see is woven into a subplot where the focus is more on Merry and Pippin's growth (figuratively and literally
![Wink ;)](./images/smilies/icon_wink.gif)
).
It's a bit like reading a novel set in WWII about two staffers in the War Office who end up going on a secret mission to Berchtesgarten, in which Winston Churchill is an important supporting character.
Well, except Churchill was interesting.
Seriously, though, he's a character from romance or epic after Rivendell. He may do interesting and important things, but that doesn't mean he's all that interesting as a character. Now, from Bree to the Ford, that's different. But that's another topic.