Here's a nice article discussing the particular pleasure of Train Simulator (nee Railworks).
Your in-game character lacks any super powers, or a sword, or even a keychain container of mace. You don't sport body armor, or even a leather jacket.
As the author points out, though, the game is well-loved by many (my father is quite the Railworks fan)
My respect for the Railworks community began to grow as it occurred to me that their passion does not require thrills, instead they are contented by life's subtleties. Their fantasies don't rely upon adrenaline or destruction, they just wish to peacefully command a Class 47 Triple Grey all the way from Oxford to Paddington.
Well, to each their own; it's fine if it's not for everybody, and I'm glad the Train Simulator team have found their audience.