Honestly this criticism is kind of weak.

His book is a telling of history from an environmental perspective. You are free to blame the europeans AND understand that environmental factors played a role in advantaging some civilizations, these things are not mutually exclusive.

And to say there is no evidence for the environmental determinism viewpoint is ridiculous. The book is full of arguments supporting his viewpoint, and it does not argue that environmental factors are the ONLY factors at play.

And i don't think he overrepresented European innovation. From wiki: "Diamond argues that Eurasian civilization is not so much a product of ingenuity, but of opportunity and necessity". I think this is an accurate representation of the book.

I don't see the book being "largely considered to be wrong in its central hypotheses". It won the Phi Beta Kappa Award in Science, the Pulitzer Prize for General Non-Fiction and the Royal Society's Rhône-Poulenc Prize for Science Books. The wiki section for praise is twice as big as the section for criticism.

From my reading of the criticisms of the book, it seems to boil down to "this book is so popular now it's cool to hate on it" or "this book is not progressive enough because it lets the colonialists off the hook". Guns, Germs and Steel is a perfectly fine book to read, just don't count on it to be an infallible account of history.