Why? Even on longer train rides (3+ days) I've never wished that I was carrying more than a book or two at most. A novel or two of adequate length and complexity is more than enough, unless you plan to be reading literally the entire time.

Sure, maybe an e-reader is superior for those 14-day treks, but the vast majority of people don't make those kinds of trips anymore considering that most of the world is reachable within a day at most.