It's unfortunate that today's generation needs a constant adrenaline rush to keep its attention. It needs to keep pressing buttons and move joysticks constantly to keep its attention.
Go to a Baseball game, and look around. Not too many people in their 20s. The young spectators are there with their parents.
Basketball, and now even Hockey (in some American cities) have cheerleaders jumping up the second a whistle blows.
Seems like the attention span of today's "intelligent youth" is limited to a few seconds. Very disturbing.
The entertainment has to be fast and furious, and that is why the average age of a recetrack spectator is probably in the 50s, maybe even the 60s. And that is why the recetrack has added slots to attract and keep people there.
The racetrack people need to find a story, create suspense, and drama. Yes, a superhorse will get the attention of many, but it will not draw regular masses to the track.
A possible solution is to perhaps run both T-breds and Jugheads(Trots and pacers) on the same day. Thoroughbred races can't run less than 20 minutes apart, due to the harrowing of the track, and the preparation of the horses(saddling and warmup). So, as soon as a T-Bred race is over, send out the pacers on an inner track (a track built inside the dirt track, as Woodbine in Toronto has), and have a race every 10 minutes.
Worth a try, what do the tracks have to lose?