I am a fan of Diamond's work in general and GG&S in particular. It sure doesn't feel like like I am "willfully misreading" him. I would lean more towards being "deaf to tone and context" (although it seems unlikely that I don't understand the context, since I have read the entire book and watched the documentary based on it). On the other hand, I have been accused of being too literal in the past, so I can't merely dismiss your criticism.

On a related note, I must admit that I was rather disappointed with Diamond for dismissing previous attempts to answer the "cargo question" for being racist rather than being false (which is question-begging).