These studies appeal to those with high anxiety about getting sick. If they can find something they think lets them predict a cause, which they can then avoid, it feels to them like they have control over what otherwise seems to be a more or less random occurrence. They then seek to recruit others to believe the same thing, which gives them confidence they must be right.
As for the researchers, they're just in it for the easy publications and maybe some grant money.
More importantly they appeal to our victim mentality. It makes everything some faceless company’s fault, evil nasty corporations making products people enjoy making people fat is a much more appealing narrative than people failing to exercise self control.
Agreed. The credibility of researchers is damaged, and it will be a while before they gain respectibility back. That being said I despise the sugar inductry as they put that crap in EVERYTHING, well, maybe not salt, but dam near everything.