That's true, and I had considered that, but I don't think that Odium would leave the humans untapped if he thought that he could invest and control them. Mainly I was leaning towards this because Kaladin's extended period of darkness seemed sort of artificial. If I were a dark god bent on destruction and dispair I would certainly try to tap into that particular broken soul, especially considering his proven talents thus far. Also Adolin's actions surrounding his murder of Sadeas seemed distinctly out of character. Again, the stabbing him in a fit of passion I can easily attribute to Adolin. The act of hiding it, though, that seemed out of character. However, I am not a dark god bent on destruction and dispair. At least, not after I've had my coffee...