The play, described as a "bucolic farce" dates in fact from 1888 but had a rather particular claim to fame which is probably what incited Tourneur to make the film. It was apparently written by one Charles Barnard but was produced for the stage by an actor/inventor/impresario called Neil Burgess (the introduction pays very specific homage to him) whose real name was James William Knell. He was also a female impersonator and himself played Aunt Abigail Prue in the stage production but what made the fame of the play was the system of treadmills and panoramas invented by Knell/Burgess which gave an impression of movement during the racing-scenes (using real horses), a system which would again be used for the chariot-race in the stage production of Ben Hur. So even if the story is a little dire, the production was, in its way, like that of Ben Hur, an important theatrical forerunner of cinema and the interest of making a film, with suitable apologies for the old-fashioned "wholesome" material, is therefore clear.
It is true it is no worse than the average US film of 1920 (sentimentality and buckled swashes rather ruled the day) but very much more interesting films were being made that same year in Germany and Sweden.