There are a few advantages of looking at the station and trains of other players.
I have seen already to see if a player is connected or close to connected to the city your assoc. plays in when he/she applies.
An other point is for new players, i often have watched the trains and station of new players to help them on the way, to give tips if they don't know where to work on and for new players it's also good to see how experienced players build up their stations or which trains they use.
For the endgame it's useless to see the trains or tracks of other players, what do you think to see which tactics they gonna use, most players have connected several cities and endgame cities have connected a lot of players who don't haul for that city in the endgame and for the prestige haulers, they have connected several endgame cities so if not all.
So what my point of view please keep the possibility to watch the station and trains and tracks of other players.