This is a difficult point to argue, because we don't have a way of directly evaluating the relative "strength" of an argument. Criticism of Diamond does point out flaws in his work, but his critics may feel that they have done more damage than the average reader perceives; who is correct? In this case, Diamond's points remain fairly substantial.
Perhaps the greatest problem in Diamond's work is the fact that he is a trained geologist, not an anthropologist, sociologist, or archaeologist. He does not have a formal academic authority to make interpretations and theories on these subjects. Nevertheless, his books, which are written in a popular science tone, attempt to tie these many elements together and portray ancient civilizations as vibrant, realistic, and entirely relevant to our own civilization. In "Collapse" Diamond makes a case for certain key factors being the cause of a civilization's collapse, and he warns against our own consideration of these paths. His conclusion, in many cases, is that human actions made conditions in these ancient civilizations unlivable, and so they were abandoned.
"Questioning Collapse" is a collection of short essays by experts in the various fields that Diamond talks about, such as the Mayan culture. The exact essay is titled "Bellicose Rulers and Climatological Peril?" ; you'll find it linked in my sources below.
Diamond argues that environmental factors contributing to the collapse of Mayan society included deforestation and land mismanagement, ignorance of changing environmental conditions, and disinterest by despotic rulers. In "Bellicose," his critics make several arguments in response to this;
- The Maya exhibited considerable land management; they did deforest the Lowlands, in order to plant more crops. They were aware of the side effects and made efforts to conserve soil and water.
- The Maya were very much in tune with changing environmental conditions and had been responding and adapting to them for several hundred years.
- The Mayan rulers were not despotic monsters; Diamond is making a judgement based on 21st-century values.
- Who decides if a civilization "collapses"? In the authors' opinions, the Mayan civilization did not collapse, it simply shifted away from its old locations and values.
Unfortunately, I find it hard to argue against the term "collapse"; if the White House and Lincoln Memorial were overgrown with jungle, Washington D.C. deserted, and the nearest humans were living in huts, we would have a very difficult time saying that civilization had NOT collapsed.
Nevertheless, the environmental factors cited by Diamond are real; drought, deforestation and poor soil have long-term consequences. The criticisms in "Bellicose" seem very apologetic, to the point of dismissing environmental changes as a negative and arguing that they are a testament to the agricultural ingenuity of the Maya.
Thus, "Questioning Collapse" does challenge and weaken Diamond's argument by addressing his tone, content and interpretations, but it does not undo his point.