This is my failure, because I made the dialog. Still it should be improved. The schedule dialog leaves players clueless what is expected from them when it opens. This is bad UI design. The dialog should give hints what the player has to do next to create a schedule.
I imagine that new player have really a hard time to figure this out.
I have no real ideas how to make the dialog it better, but I know the current state is bad. We should try to improve this.
Would tooltips help, I wonder? Perhaps a video tutorial on Youtube?
For an empty schedule, a small help text could be shown:
"Please click on the map to define the stops the convoi will hail." or so.
I think this will help tremendously already, and remove one of the biggest obstacles new players might face when trying Simutrans.