Most researchers who publish studies are unfamiliar with the scientific method and hypothesis nullification. Either that, or it's not in the interests of the publishers to properly apply these concepts in their studies. We've gotten to a scary point where "science" is now getting more and more into the hands of the public and become a consumer good purely for consumption in the form of news. People love studies that confirm something they already believe. It's bad for business to dispel myths that people have an emotional investment in.