Why is isotropy so prevalent in spatial statistics?

Click on the DOI link to access the article for free at the publisher's website.There are many reasons for the popular use of the isotropic or geometrically anisotropic covariance function and variogram in spatial statistics. A less known reason demonstrated in this paper is that an isotropic or geometrically anisotropic model would be the only choice in certain circumstances, for instance, when the underlying random field is smooth enough.Peer reviewe