Wow. Way to wave away something you apparently find inconvenient to consider. There's no element of blame in Jaynes's explanation, or any attempt to label them as primitive. He's talking about people as recent as the ancient Greeks, the ones who fought the Trojan War. He also doesn't claim that communications from the right side of the brain are valueless. Sheesh, learn about something before you dismiss it, why don't you?
Not in so many words. He just suggests they are irrelevant. Then, and presumably now.