I addressed this point earlier. There was a Trojan War, although the version presented in the Iliad is embellished. But you can go see Troy, and the rivers and streams mentioned in the Iliad. You can find every city the heroes came from. We know what their ships and weapons from that period looked like.

The actual poem describes gods, but look at how it does it: when the camp of the Achaean host is struck by disease, it is the work of Apollo shooting his arrows of disease. This is not because someone was "making up" Apollo. The Greeks of Homer's time (or at least of the Heroic Period) actually BELIEVED that this was how diseases could be generated. As a result, that isn't speculative fiction. At worst, it's poetic license, and at best it's firm belief that has since been proven wrong.

Yes, there are a few scenes where the gods participate more directly and talk amongst themselves. But once again, this was how people explained what had happened. It is no different fundamentally than saying Yahweh saved the Children of Israel by parting the Red Sea. We don't consider the Bible to be "speculative fiction," however. We also don't consider the Epic of Gilgamesh, or the Mahabharata or Bhagavad Gita to be speculative fiction. People believed it was true. When all these stories were written down, they had been passed on as part of the oral tradition of their peoples for generations.

That, quite simply, is MYTH. It is fundamentally different than speculative fiction. It is a defunct form of expression because our modern world makes it nearly impossible to generate new myths. Information is recorded almost immediately and supposed facts can be proven. Urban legends are disproven on Snopes.com almost immediately. The closest thing we have today is when academics (or the entire community) "spins" history to prove a certain point for propaganda purposes.