Diamond is pretty well regarded even in among academic historians. I strongly suspect believe that /r/anthropology is responsible for this perspective that Diamond is poorly regarded among historians. Almost any serious historian agrees with his thesis: larger arable land coupled with crops and animals more suitable for domestication led to greater population levels and social development in Eurasia than in the Americas, which is the main reason why the Columbian exchange was so one-sided. Diamonds ideas laid the foundations of many serious and well regarded historians, like Ian Morris.

I'm also seriously baffled by people who try to portray his views as racist of eurocentric. His preface explicitly spells out that Europe was a backwater until the early modern period. In fact, a large part of the motivation behind Guns, Germs, and steel was to debunk the idea of wester cultural or racial superiority, and provide a compelling counter narrative to those explanations of Eurasian-American divergence.

"Europe was a backwater"

This sort-of goes too far. The Roman empire at its height was very much not a backwater. What is pretty unique about Europe is the subsequent enormous loss of civilizational complexity in the Early Middle Ages combined with the fact that it could, albeit 1000 years later, drag itself out of the hole again.

Sure, but the British isles, which would eventually become a preeminent colonial power, still was a backwater even during the Roman Empire. France and Spain less so, but most of the Roman Empire's most developed regions were in the eastern Mediterranean. In his preface, he points out that from the span of human civilization from 2500BC to 2000 AD, Western Europe has been dominant for only a few centuries.

The Eastern Mediterranean was rich and civilised long before and after Rome was a backwater. At the earliest Northern Italy, Germany and the Low Countries were at the technological frontier in the 1300s. Pretty long gap, quite a distance. Europe outside the Mediterranean only really became important in a way anyone else noticed with the Age of Exploration.

And he points out how China could have easily been "first" if it weren't for the whim of an emperor. He argues somewhat successfully that the geography of Europe made empires less successful, and therefore executive decisions had smaller "blast radii".

I believe you've misunderstood the parent comment.

Also - generally speaking, I think being able to speak (or write) in a manner that's compelling for audiences across broad backgrounds, rather than just their niche community is a skillset to be admired.

Science does nothing if people do not believe in it, or do not engage with it.

I definitely agree that this does not give academics license to veer entirely outside of their expertise and use their credentials in the field to hide this (eg: Diamond). But I think not trying at all is worse. Far worse.