I don’t understand why this comment is made as frequently as it is. Do you think the authors of the paper aren’t aware of this fact? Do you think they didn’t think of this when they did their research?
Having said that, there is absolutely a valid question of did they incorrectly rationalize their approach, or rely on studies that did so, such that they in their own minds thought they addressed the issue when in reality they hadn't. My sense is that parent comment to which you replied probably didn't read the study, the original studies, or consider the point I'm making (sounds like a shot from the hip after reading the title), but the viewpoint isn't necessarily invalid.
Given that some authors have a very real and emotional attachment to ideas they are trying to prove out in such studies... the rationalization error is one to watch for...
I am tired with people just saying that correlation does not always imply causation. As if this is somehow insightful. Whenever I see this I think less of the person who writes it. It’s as if they don’t have enough common sense to assume that authors of a study that relies on statistical analysis don’t know this.
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.