Gregory's ServerIt's vanity and the purity impulse (moral reductionism plus decontextualization) combined with silver-bullet thinking (causative reductionism plus decontextualization.)
"I'm so clever that I can see the real answer and now *I'm* clear of the secret lie that's been right in front of you this whole time! I'm clean and I want you to be clean too!"
I think a lot of this sort of quackery in the US is because of our health care failures. People are desperate.