Given the absence of any response, it is quite clear that there is no interest for a virtual horse racing game especially one aiming at the gambling audience.
Fisrtly, the video-game demographic is dominated by children/teens and young adults, none of which would have a profound interest in gambling. Thus the 'earn real money' aspect of the game would not make such a game successful and may even deter potential buyers from it because there is always a balance to earning real money: losing it.
Secondly, there truly is not a huge market in the virtual horse racing game genre on all platforms (Consoles and PC). Horse Racing in real life is extremely popular as a spectator sport, but this view does not translate to gaming. Recent dedicated horse racing games have not proven successful in sales and popularity simply because it is such a niche genre.
Ultimately, earning money and experiencing the jockeying of first place should remain where horse riding does it best: real life.
