Sydney Trains believe that Homebush is west of everywhere. From Homebush station, the only direction you can catch a train in now is east (towards the City). Want to go to Parramatta from Homebush? Then you need to go to Strathfield first and come backwards to get to Parramatta or for that matter anywhere else west of Homebush.
Sydney Trains and the bureaucrats that run it nevertheless cease to amaze.