To save people reading the very long writeup, a summary: "blah blah blah blah Jared Diamond bad blah blah blah blah nitpick nitpick blah blah selective interpretation blah blah". Many years ago I dated a history postgrad who complained that to get anywhere it was more or less mandatory to cite and quote some academic historian who was in fashion back then, can't remember his name but it was a beardy guy who was on TV a lot at the time. Looks like things haven't changed much since then.