Symbols are not "intended" for value storage, symbols happen to be used for value storage. Symbols have exactly the same properties as, say, named constants in C, and thus fit in the same niche. They also have the properties of variable names, and so fit in that niche too. Symbols are a generally useful datatype, and they are no more intended for just "value storage" than cons cells are intended for just list construction.
A list of strings is still a list, which is not what you said; right now, it's a list of symbols, and I don't see the benefit of a list of strings over a list of symbols.