As an open ended cargo launcher, VERY fast, but short, lunar rail likely makes sense. With the caveat that the flight plan needs to be VERY secure. Why, well read the wonderful book!!! But as a way to send cargo into lunar orbit or even even back to earth it probably is the cheapest and most sustainable option from the Moon. And IF we ever establish a permanent settlement there, which my Heinlein infused childhood dreams encourage, we will want such. And the effort required to accomplish the former likely wouldn't require much more expense to provide that. Now whether rail links between separate lunar bases are cost effective or not depends on the distance. Might make more sense to launch into low lunar orbit and come back down at the destination.
I’m still waiting for resource gathering from asteroids…