The 'facts' that I referred to are the results of correlation studies as published in science journals. The diets you mention are mainstream fads.

You're right, though, it is frustrating! My personal opinion is that it is the way we use food for pleasure and comfort that it is to blame. We are literally getting high on what we eat, which is deleterious for health if performed without break for long periods. But there's no obvious way for a scientist to address this idea at present; it would be considered too subjective and thus ignored by the majority.