Massimo Pigliucci considers (again) the question as to why irrational beliefs mimic science (In a blog post and in a co-authored paper (link currently broken on this)). The idea:

In the paper, we develop and extend an epidemiological framework to map the factors that explain the form and the popularity of irrational beliefs in scientific garb. These factors include the exploitation of epistemic vigilance, the misunderstanding of the authority of science, the use of the honorific title of ““science” as an explicit argument for belief, and the phenomenon of epistemic negligence. We conclude by integrating the various factors in an epidemiological framework and thus provide a comprehensive cultural evolutionary account of science mimicry.

A critical issue, I think, is that the purveyors of this stuff themselves fail to understand the difference. They mimic science (badly) because they think they’re doing it right. Moreover, everyone thinks this is true of the people with whom they disagree. The comments on the the Twitter feed quickly illustrated this point.