The dubious part is the implication that being the "Land of kami" sets Japan apart from all other countries; that it is somehow more sacred.

If as claimed, kami are everywhere and a part of everything, then all countries are the Land of kami.

Certainly, none of the concepts that are thought of as being kami are unique to Japan. Ancestors, protective group spirits, spirits of place, forces of nature, natural objects, animals, plants, and mythic people — all as kami; all also have analogous aspects in other cultures. These cognates as well fall under the rubric of kami.

So yes, Japan is the "Land of kami" and is sacred, but then so is every other land.