You don't get the economies of scale needed to justify high-quality, regular rail service along the more quiet routes.
Look at China's high speed rail network. Only a small minority of routes manage to break even, and the rest of them are a huge financial burden that the CCP just accepts because achieving a huge engineering feat creates a sense of national pride.
Look at China's high speed rail network. Only a small minority of routes manage to break even, and the rest of them are a huge financial burden that the CCP just accepts because achieving a huge engineering feat creates a sense of national pride.