> This is kind of akin to that artificially absurd example of "on average, every human on Earth has one testicle".
No. If I claim everyone has 0.5 testicles, that's bad science. If I randomly choose a large enough number of subjects and report that approximately 50% have two testicles and approximately 50% have no testicles, with error bars, p-values, etc., saying that you don't trust this because I am trying to make a career and you prefer to follow your own experience, which after looking between your legs clearly shows that 100% of people have two testicles, would be quite stupid. If I chose only 3 people, or all of them are male or female, or I make any other mistake, point the mistake, but don't attack me personally, and much less science in general.
For example, I followed the link to the study by the Nielsen Norman Group and then the reference to the study of Piepenbrock. They explain well their sampling method, with different groups by age and depending on vision problems. You can clearly see the individual results and the variance, and it is obvious that generalizing to the 100% of population would be wrong, but there are some very clear trends. Calling these researchers "someone trying to p-hack their way to a publishable result that's sensational enough to advance their career" without any proof whatsoever is insulting.
To be clear, I do not intend that anyone changes habits because of these studies. I agree that this is subjective enough to make it a personal decision. But as a scientist trying to make a career, I found the above comment very disrespectful.