Is this a productive exercise of skepticism?
Skepticism is always appropriate concerning one person's claim. People are fallible. Scientific and empirical methods have shown themselves to allow progress in development of knowledge in spite of individual fallibility. Paradoxically, it's likely that on any given issue there's some individual who's closer to the truth than the consensus is. This is why individual diversity is valuable. Especially when it comes to long tails. Extreme views are almost always wrong, but when they're right, they're very very right in comparison to the middle path.
It's important to understand particular common failures of human reason, and to base skepticism on this knowledge. We strongly tend to over-perceive pattern and causality. We also (with good reason) greatly value a story that explains what we know. We're really bad at assessing a story against all possible stories we haven't heard and all the evidence we don't know. We do tend to falsely think that we understand, based on quite flimsy evidence. Science isn't immune to the narrative fallacy, but a good scientific theory is falsifiable. Science is interested in determining casual relations, and has had some pretty good success in doing so.
When we consider a historical event (world war 1), the skeptical position that events don't a cause is defensible. We can imagine causal theories and the associated counterfactuals, but the “all other things equal” condition can never be met. For complex (but less unique) things, like murder, it becomes possible to infer patterns and test what causal relations are consistent with what we see. Perhaps we can even make useful theories about war in general.
For science, it's natural to consider causality on attributes of potentially isolated systems. This allows a bit more precision in what “all other things” means and gives a strong suggestion of how an experiment could be structured. When something important happens, it's natural and adaptive to award praise and assign blame. We'd like a story about how we're going to bring it under control, and that requires causal explanation. It's adaptive even if we often don't get it right. People are selective in their use of skepticism, of course (confirmation bias). I can come up with many stories of why I'm skeptical about school and not about heritability. One point about skepticism, or criticism in general, is that criticism without positive suggestion is much weaker than suggesting a superior alternative. Early theories are certainly incomplete, possibly entirely wrong. That a theory can be criticised doesn't invalidate the field.
The success or failure of a scientific field isn't determined by it's success in answering criticism of it's philosophical foundations. It's whether the theory “works”. Physics is highly successful even though it's founded on the unwarranted and unprovable hypothesis that there are universal physical laws.
It's mainly when a new theory gains mind share that approaches are replaced and theories abandoned. Sometimes an entire field or sub-area can fade if it ceases to be productive. It's unlikely that this will be caused by a new criticism, but old criticisms that dogged the field all along may seem compelling in hindsight. This could happen to string theory in physics, which has so far failed to generate testable predictions. Either for heritability or evolutionary psychology.
Occam's razor. Preference for simple theories. As simple as possible (and no simpler). Preference for approaches that have been productive in the past, or in other areas (analogy). Science: testable theories and research programs.
Explanatory and predictive power. Causality. Can we manipulate? Absence of correlation does disprove theory of substantial simple causation. To oversimplify, ~correlation → ~causation