Horse betting has been established to be just that: Betting (I have no clue if that's really true, no offense to the hn horse racing crowd). There is no big institution money that says otherwise. There are no startup wizards working in the field. Nobody claims they are going to change the world.

Crypto on the other hand is sold as the future, and the people who miss out on the future are losers. The tech is really complicated, you don't understand what's going on, but, clearly, some very smart people do and they are convinced.

The point being, it's a lot easier to disregard horses than it is to disregard the future.