This only benefits passengers if it comes at the same time as fixing the fare structures.

At the moment it's often cheaper to buy a split ticket, because it can be inexplicably far more expensive to buy a ticket between station A and station C than it is to buy tickets between stations A and B, and B and C on the exact same train. This would be impossible in a tap-on-tap-off type system; if it's just used to lock people out of cheaper fares, that's not good.