Personally, it's the difference between, say, The Spartans/300, versus the likes of The Odyssey or the tales of Jason, Theseus, or Perseus: the fantastical element. The former has basis in reality whereas the latter are legends, fantasies, so absolute historical accuracy just does not factor to me. Odysseus encounters gods and nymphs, he blinds a Cyclops! Meets Circe! Loses some of his crew to Scylla while trying to avoid Charybdis!
If someone wanted to do a film on the Peloponnesian wars then sure, I'd prefer a faithful depiction, however odd the true armour may look, and goofy painted statues in the towns and all. But a Greek fantasy flick, a war that ultimately happens because the goddess of strife and discord was barred from attending a wedding? Hell yeah, Rule of Cool.