I disagree with the initial premise that regulatory policies are easy to copy. From later in the article, fee caps are one of the major ways the government enforces this and they have to be:<li>High enough that a well-run railway makes a profit.</li><li>Low enough that they make rail an attractive choice for consumers.</li><li>Scaled with demand to encourage investment in infrastructure.</li>
This requires that the regulator has deep knowledge of the industry. The way that this normally happens in the West is to hire people from the industry into the regulator, which is leads to rapid regulatory capture.
Having a regulator that maintains independence over a long period seems to be the Japanese trick, but the article doesn’t mention how this is done at all (policy? Culture? Laws?) and without that, there’s no way such a model could work.