I believe they have done this format to generate maximum exposure to the public.
Lots of people finish work at lunchtime on a Friday so things need to be happening on Friday afternoon to generate interest.
You want the main finals to be running around lunchtime on the Saturday as that is when most people are around in shopping centres, you want the main event to happen in front of as many people as you can to (hopefully) attract new people to the sport.
Sunday is similar to Saturdays, most activity being around lunchtime / early afternoon.
I think they have got the format spot on for public exposure (why it's in a public place after all), from a pure racing perspective I'd prefer a single class per day too but hey, it's all about the show
