My interpretation of the creation myths goes as follows. The goddesses shaped the physical land (Din), laws of nature (Nayru), and the life forms that inhabit it (Farore). Such life forms included all of the various races we see in the games, Hylians and Oocca included. As Steve pointed out, the original wording was that the Oocca created Hyrule, not the Hylians themselves.
The Oocca are also said to be, among all the races, the closest connected to the goddesses. Since the Oocca clearly seem to have a great skill in technology, just look at the City in the Sky, it is likely that the Oocca passed down some of their skills to the Hylians, who's royal family was able to communicate with them with assistance from the Dominion Rod. Look inside TP's Temple of Time, it's fairly advanced technologically, with the great elevators and electrical gates and whatnot. The Oocca didn't physically shape the land that is Hyrule, that was Din's doing. What I think the Oocca did was assist in the development of Hyrule as a kingdom by giving the technology needed to build the kingdom to the Hylians. After all, Hyrule is comprised of many races, yet the Hylians are in charge, and this may well be due to assistance from the Oocca.
I hope I got my facts straight here... >_>