Your criticism of the testing methodology is fair and valid. However, I see this as a test controlling for a single variable to the best of the ability of whoev

Your criticism of the testing methodology is fair and valid. However, I see this as a test controlling for a single variable to the best of the ability of whoever made it. I am not sure what a better testing methodology would look like. Which is why I see this at least as an indication of what is systematically going on.