On "Minerality" In Wine, A Confusion In Term?

Each time I hear people describing wine as "mineral", I frankly get confused...  After all, what exactly does the term mean?  That the wine taste of rocks?  
The WSET suggest that "mineral" should be used when the wine is perceived as "earthy", when it has an aroma of petrol, or rubber, tar, steel, or wet wool.
Yet, can wine pick up the taste of "minerals" from the earth it originates from? After all this talk of terroir from wine producers and the emphasis on their slately, gravely, sandy, chalky, limestone soils they grow their grapes on/in, it is easy to start to beleive that, indeed, wine can taste of "minerals".
However, studies were conducted on this matter and Jamie Goode, the most respected wine scientist from the U.K., in his 2 books "The Science of Wine" and "Authentic Wine" make a pretty good case that there are in fact no conclusive evidences that grapes pick up any minerals from the soil.
So why professional tasters of all levels insist on using the term minerals when describing a wine?
In its systematic approach to tasting, the Italian Sommelier Association use the term "sapidity" instead of minerality. It is used on a continuum that goes from tasteless to salty. 
To them, "sapidity" refers to the "micro-sensation linked to the presence of inorganic anions together with metals & organic anions. It is related to the "hardness" of the wine and express a "savory" sensation, similar to salt on the tongue. Sapidity, they claim, contribute to enriching the wine structure and it is an positive element of quality. They argue that acidity and sapidity are perceived by the same type of gustatory papillae. 
It would then make sense that the two are closely related as the strength of acidity itself is related to the ph level and the quantities of salts being present in the wine.
Within the context that italians tasters use it, would "sapidity" (saltiness) be a more accurate descriptor?