Fluoridation opposition is a joke. It is like a quick shorthand that the person doing the opposing is nuts, a pest, doesn't know when to shut up.
Now leave aside fluoride for a minute. Consider an actual impunity. Consider the boardroom at R.J. Reynolds. Hey, that banality-based dismissal starts to look like a pretty sweet deal!
"Nobody's going to investigate us. And if anybody does, nobody's going to take them seriously because everybody knows tobacco is safe - anyone who stands up at their city council meeting and tries to talk about tobacco and nicotine, the council is going to collectively roll its eyes as though you had said 'fluoride.'"
Or at Chevron or Shell, "Ever since Pons and Fleischmann you can't get five minutes on the stuff. And that's good for us!"
The fluoridation blanket - this spreading anti-Midas touch of being accused of unseriousness, ideas just too far out for polite discourse - starts to look pretty good! "Hey, how can we get some of that banality!"
To unpack the shorthand a little here, consider the false positive. I'm making up this story: to fight terror, we fire off a little Raytheon box the size of a baseball. There's a flash of white light, and everyone in the vicinity finds themselves home in bed with tinnitus that will last for the next three weeks. Occasionally the tinnitus leads to a car accident. 99% of the people who were there were false positives, but we got a terrorist in the process. I know it's fanciful. Okay, so the thing that really protects us is the conversation-ending power of perennial gadfly issues. To be Cheney or Peter King talking about Ned Lamont is one way to (try to) shut down conversation. Another way is to affiliate your efforts with something people are so bored of, that they see it coming and say "oh god, not that again." Any journalist, or person on the receiving end of the Raytheon box tinnitus, who tries to get other people to pay attention, is going to get eye-rolls in return. Which is the right thing to do when they're wrong. And if they're right, it helps cement the bricks of the impunity.
See also: Christine Todd Whitman and harmful dust at ground zero, Gulf War Syndrome. Aha - using Kucinich's claims of having seen a UFO to shut him down.
The voice of conservatism, common sense, Occam's razor, also has a point here. Fancy things, entire cottage industries around far-out ideas, Dave Emory, what's the name of the one Andy likes, the Prevailing Winds catalog, and if you go back a few decades the first generation of JFK "researchers" and the mini economy around it, and in the notes of From Hell, Alan Moore talking about a similar type of culture around Jack the Ripper, with finding one more grapestem and poring over it -- the money and the vested interests in just telling more fairytales forever, satisfying an audience with a hunger for far out stories, Alex Jones -- this institutionalization is definitely a problem that discredits the ones who are right, if there even are any who are right. The ability to "go to a zone," lose sight of a forest for the trees of listening to John Stockwell in Campbell Hall on a UC campus, Barbara Honegger, Philip Agee, Daniel Sheehan, would tend to bolster the conservative with a small "c", who says, this is all really convoluted, involved shit which tends to go against Occam's Razor. It just sells a lot of tickets. So then the waters are muddied, which I say without a bias, or an intentional dog in that race, except I think if it is going to be public policy of the public's elected representatives to allow and support hurting a certain level of innocent people for the greater good, it should be out in the open what that is, and if a Prevailing Winds type of speaker actually had something credible and true, it would be kind of a pity if they weren't taken seriously because their millieu was seen as a cesspool for conspiracy theories. And that, too, would be a tradeoff, because the false-positive lives you decline to try to save, might, or might not, be offset by the good diligent caution of not wanting to end up like Pierre Salinger, or leap really quick, too quick, give everyone cipro too hastily for their anthrax, then finding out that insufficient care had been used and the cipro was actually poison. Or hop on the Thalidomide train because it sounds like a panacea, and by the time the dangers are exposed, it's too late.
To act hastily or wrongly is fraught with problems. To not act because you're dithering over the danger of acting hastily or wrongly, is also fraught with problems.