I really would like to know: what's the point of this?

I mean, there is NOTHING you can do about it. It would be okay, if you could for example buy some special chocobo gear, making your chocobo a bit slower or not so easy to ride, which will in compensation get rid of the weather effect, but the way it is, it's just a lottery.

For example a "fair weather" chocobo. Then in this impossible rain-swept desert of south thanalan, every single race is cloudy, rain, storm, which simple means, that you need 10-15% more time to beat the course.

Sure, it's nice when you got the right weather, but then again it's bad for "foul weather" chocobos...

I don't really get the point of this. It's just throwing a dice and that's it.