I may be jaded and cynical but it seems to me that when people just write, "Correlation does not always imply causation" they are trying to demonstrate how smart they are and how dumb the authors are. I notice this comment come up a lot when papers by social scientists are posted on HN. It appears to me that the people who make such a comment are making a low effort attempt to discredit research by pointing out some trivial statistical fact.

I see comments of this type all the time on HN. People criticize posted research articles by pointing out some obvious reason why it might be false. As if this obvious roadblock wasn't thought of by the authors. Such people almost never read the actual article and have a tendency to believe that their non-expert opinion on a possible issue is sufficient to discredit the research article.

On HN it seems to me that most people commenting on research in the social sciences believe that their cursory understanding of a topic is on par with the knowledge of experts in the field.