Chocobo racing suffers from the same issue the other gold saucer games (Verminion, Triple Triad) have too. It was designed overly complicated and too time consuming. People wanted fun, easy to understand and above all quick mini games. Something you could do while waiting for a queue to pop or just to kill some time. Instead we got massive time sinks, huge grinds and game mechanics you need a guide to understand fully.
Some dedicated people put all that in and those are the ones who got maxed Chocobos, but the majority of players probably just quit long before that.