Thanks for the honest discussion but I disagree.

For me that's like saying we should carry on plastering the wall while the underlying wooden structure is rotten, makes no sense at all to me, but you and others are welcome to persist in the folly.  

 It does both the things I mentioned. In some ways its quite similar to Chorine at a small level it does not interfere greatly with the macro process but will inhibit it. Things will eventually ferment still and horses wont get fluorosis at the right levels but what happens when they accidently add too much (those things do happen) and what are the cumulative effects over a lifetime?
  
Unlike Chlorine (typically linked to bladder cancer) which is easily filtered out by low cost Carbon, Fluoride doesn't and Calcium Fluoride is not the same molecule as the Sodium Fluoride they add to the supply. As you keep reminding us its only been 75 years in the US.. .that's not even a full human lifetime to evaluate it. You also have to take into account with the yeast and microbes these things also live in us. So while some of these yeast may only be inhibited in large vat for producing alcohol, what's that doing inside us where levels would never be as high? I would prefer the precautionary principle in this case.

Out of curiosity would you also defend adding Lithium to the water supply? Because believe it or not people have suggested that to stop people killing themselves! Surely that more important than teeth right?!