Guns, Germs, and Steel was most certainly not about "how and why European societies were able to advance themselves so much farther ahead of all other civilizations". The concept of "advanced", or being "ahead of" is inapplicable. It's a book about sociocultural evolution.
Additionally, Diamond is pretty ambivalent about the "winners". Diamond wrote an essay on the subject of agriculture called "The Worst Mistake in the History of the Human Race". He closes the essay with "As our second midnight approaches, will the plight of famine-stricken peasants gradually spread to engulf us all? Or will we somehow achieve those seductive blessings that we imagine behind agriculture's glittering facade, and that have so far eluded us?"
Additionally, Diamond is pretty ambivalent about the "winners". Diamond wrote an essay on the subject of agriculture called "The Worst Mistake in the History of the Human Race". He closes the essay with "As our second midnight approaches, will the plight of famine-stricken peasants gradually spread to engulf us all? Or will we somehow achieve those seductive blessings that we imagine behind agriculture's glittering facade, and that have so far eluded us?"
http://www.ditext.com/diamond/mistake.html