It’s the nexus between activist funding, friendly media channels, and the social promotion due to like minded folks interested in pressing a specific agenda that often causes some bad science and studies to leak out.
Where there is a large industry, there is a large anti-industry. To me, the point is that there is a large potential for bias in either direction so incentives to reproduce, validate, and otherwise test results need to be found and somehow added to the process. I would say that despite the size of this industry, this particular issue is the tip of the iceberg when you consider all the industries that have a significant impact on humans.
Goes both ways of course.