The reaction from the social sciences and the mainstream media elites who need the social sciences to seem science-y was about what you would expect to him making his case yet again: 'shallow' and that he doesn't understand what it means 'to study human diversity' - in other words, he is a geography teacher trying to invade the big pants super-scientific world of anthropology.
You can stop laughing now.
While older anthropologists made at least an effort to embrace science, the younger generation has thrown of all pretense of being anything but sociological self promotion of WEIRD - Western, Educated, Industrialized, Rich, and Democratic - ideas so patronizing 19th century Brits in colonial Asia would think the modern humanities have gone too far. Modern anthropologists are not having it or Diamond. Even his seminal "Guns, Germs and Steel" should not be taught in any basic anthropology class, one of them sniffs in a quote included by anthropologist Barbara King at NPR. Modern anthropological fundamentalism absolutely rejects Diamond and they sure seem to resent his popularity.
Western social science academics don't like having their superiority challenged, sure, but no one wants to be told that they don't know what they are talking about. One funny review I got about Science Left Behind was by a hard-left old journalist who said it was terrible, while comparing it nonsensically to a book about social psychology written to slam Republicans - the two books had literally nothing in common. But a chapter called "The Death Of Science Journalism", which blames aging, hard-left journalists for ruining the public's trust in media is not going to be well-received by aging, hard-left journalists hoping to retire at Huffington Post, so he took a carrot and stick approach - slam the naughty book puncturing feel-good fallacies and applaud the one that matches the 'correct' political mindset.
Now, maybe Diamond's book is terrible, he is big enough that the publisher is not sending me proofs for review. Even Elvis had bad albums - but that doesn't make Diamond wrong in his overall thesis.
King asks the obvious question at the end of an exhaustive collation of the criticisms of Diamond: if he is wrong, why isn't anyone instead reading books by anthropologists making a better case than he does?