> In fact, people do believe weird things about salt; there is a widespread and unsupported belief that moderation of sodium intake is a key public health concern, which it is not.

It's not an unsupported belief. Studies have shown that high sodium intake is a significant contributor to hypertension. Here is one such study: http://eurpub.oxfordjournals.org/content/14/3/235. There is debate about whether consuming several thousand milligrams of sodium a day adversely affects blood pressure in everyone or only in some people, but that it's a major contributor to hypertension (9-17% of cases) is supported.

If you have specific criticisms of the methodology of those kinds of studies or if you have links to sources that dispute the above, I'd be interesting in reading them.

Or are you saying that what's unsupported is the notion that the above makes sodium intake a key public health concern?