I come from a country, where horse racing isn't popular at all. I mean literally nobody gives a sh*t about horse racing where I live.
AFAIK, horse racing in popular in the anglo-saxon countries like the UK and USA. I don't know why. I don't mind betting on horse racing, but I just don't find it interesting. I can't predict which horse is better than the other horses and can't analyze the performance of the horses and their riders. I don't think that crypto casinos actively promoting horse race betting around the forum would change anything. This sport simply isn't popular in certain parts of the world.
And what i do think is that, when horses were a pretty much always available commodity, the game of horse racing was pretty popular and one that was enjoyed by very many people all over the world, but today, horses have become very scarce, and pretty expensive for those who still have it, so instead of spending so much money to host horse racing games, people now refer to spend less to host even games that are more interesting than horse race, as we have a lot of options today when it comes to sports.
In theory it is about knowing the game and the horses, but for real is a super-difficult game to make profit from. It is difficult to get enough good results in a systematic manner not to mention to have any advantage over the punters that are really well into the business. Anyway, I think is more popular with old people, that can spend a whole evening drinking and watching it.
Like today, football matches, and other forms of sports that invoiced human participation can be predicted easily depending on how well and time the gambler have spent in studying the players and teams in general, so outcome of such games can be easily predicted.
But for horse racing, and other animal games, this is difficult because animals don't have a long lifespan like we humans, so for the years such animal in involved in the sporting event, its not long enough for gamblers to build a clear statistics and performance ratio on them, which is what will aid gamblers in deciding which animal to bet on each time there is a game.