[Reincarnate]

Cavernio: You can take virtually any ingredient from pretty much anything you eat or drink and crank it up to levels that cause harm in some way. Obviously that doesn't mean you should stop eating or drinking. What matters is that we look at the effects of those components at different levels and see what's considered beneficial/safe/etc or harmful/unsafe/etc.

Fluoride is *already* present in natural water supplies. The question is whether or not the slightly boosted level is harmful. The evidence suggests that it's not harmful even when assessed over a variety of metrics (not just cancer). In fact, it's actually quite helpful, and helps wage war against tooth decay. It's been studied pretty extensively by countless independent groups over the decades.

Some people may have an allergy to fluoride, but it's quite rare, and there's no evidence of any adverse reaction from the levels found in fluoridated water. Some people claim to be affected, but from what I've read, it seems to be most likely hypochondria/placebo effect/reactivity bias in those scenarios.

Tooth decay, on the other hand, is some health-crushing shit you definitely want to avoid. It can be costly and painful to address. So the advantages of fluoridated water far, far outweigh any "risks."

To address your last point: Some people know they're peddling snake oil, and some genuinely believe in their own nonsense. Either way, it's still a problem. Either you've got the blind leading the blind, or people that know better who are deceiving others for personal gain. The placebo effect is powerful, but it's a problem when people are systematically trained to distrust science/evidence and accept hocus pocus as a substitute. Then you have crazy parents who don't want to get their kids vaccinated, or who think it's okay to push religion into the science classroom, and so on. In the end, it's just a lot of fearmongering and ignorance.