Reading Luisa's svithe from last week, I wrote the following comment. Which I decided I wanted to save here as well.
We just finished the Second Nephi Isaiah chapters with our kids, which means this will be our first successful readthrough of the entire book. Huzzah!
But Isaiah's got me thinking similar questions you post about the war. Why all the bother of scratching this stuff into plates. I haven't arrived anywhere as comprehensive as you have, but I have had a few thoughts.
If I were making a book which I knew would be the only thing of my culture to survive, how much of myself would I want to include? Wouldn't I be better off filling some of my precious space with Hamlet? "The Horse-Dealer's Daughter"? "Zoo Sounds"? Yeah, I'll include some of me, and if God's telling me to keep a spiritual history I will, but I have to fit in some of this other stuff as well.
So I'm guessing Nephi didn't know we would keep most of the Isaiah he transcribed. He even apologizes for giving us something we probably won't understand. But he can't help himself.
And that insight, though small, helps me understand Nephi a little better and to better appreciate his goals.
Perhaps, someday, that newly opened door will reveal further insights.