It's a small change, not like it took them much effort to change this. This change keeps chocobo racing "balanced" in that you can only feasibly do it once per day, but does mean you don't need to progressively do the race later and later each day. Now, I can, for example, head to the circuit every day at 2:30 PM for a race, and considering the 2-hour cycling race schedule, this is quite a convenience for now, as I'm running C2 races (1 every hour), and will be a godsend when my bird is capable of winning C1 races (1 every 2 hours).

As far as making it ever 8 hours... I'm not so sure I agree. Granted, you can make a lot of money in abyssea as it is, so one can probably say that no balanced is required at all when it comes to money making ventures, but chocobo racing is old content, for people who aren't high enough level to do abyssea outside of buying a leech spot. Compared to other old methods of money, chocobo racing is simply SICK for the time investment involved. As it is, I go down, talk to an NPC, and pick up my 50k for the day. Once you're past the (admittedly rather difficult) initial investment of raising a good racing bird, it's very low effort past that point, and very high returns.