Maggie's Farm

There's a difference between eating something (anything) and eating that same thing in excess.
Salt in itself is not a problem (except ruining the taste of almost everything it touches if used in more than miniscule amounts).
But the amount of salt contained in many goods most of us consume on a daily basis is far higher than the human body needs or in some, maybe many, cases higher than is healthy.
The kidneys have trouble getting rid of it, leading to kidney stones (just one reason those form, but a factor).

The problem though with most dietary regimens is that they tend to go for extremes, as do politicians.
So instead of a diet telling you to limit your salt intake, you get diets that tell you to eat no salt at all in any form.
And those diets may well have a point as you're almost certain to get your daily recommended dose just by eating a few slices of bread and having some ready made salad dressing on your letuce at diner. The canned soup as starters and the sauce mix used to create the sauce for your steak only make things worse, as does the prepackaged desert.

of course, special case. They need the electrolytes too to compensate for loss while sweating.
But you'd hardly recommend your average person drinking salted water by the gallon, would you?