That's what you get when you have a scientist try writing a book that's simultaneously popular science and popular history. And judged as a popular history GGS

That's what you get when you have a scientist try writing a book that's simultaneously popular science and popular history. And judged as a popular history GGS does get a lot of things wrong and isn't up to the standards historians work to hold up. But on more scientific questions like "why there weren't diseases endemic to the new world that would affect Europeans in the same way that smallpox did to the indigenous populations" it does a good job. EDIT: Really, the reception to GGS is probably one of the best illustrations of what Thomas Kuhn was talking about in The Structure of Scientific Revolutions about different paradigms having different rules that I can recall seeing in my lifetime.