We all know that there are movies out there that don't deserve their reputations for one reason or another. I won't try and pretend Troy is a masterpiece or anything, but I do think it's better than a lot of film critics have given it credit for.
The film opens with King Agamemnon of Mycenae (Brian Cox) embarking on a campaign of conquest to unite the Greek isles under his rule, with the reluctant aid of Achilles (Brad Pitt), the mightiest warrior of his day. While this is going on, Agamemon's brother, King Menelaus of Sparta (Brendan Gleeson), is looking to make peace with Sparta's old rival Troy, and hosts the Trojan princes Hector (Eric Bana) and Paris (Orlando Bloom) for a celebration. All seems to be going well, except that Paris has fallen in love with Helen (Diane Kruger), Menelaus's wife, and takes her back to Troy. Hector is naturally furious about this, but given that his choices are heading home and hoping they can withstand the Greek armies or sentencing Paris to certain death, he chooses to stick by his brother. Their father, King Priam (Peter O'Toole) feels the same way, and he's certain the walls of Troy can withstand any force. He'd better hope so, because Hector's anger is nothing compared to Menelaus's, who begs his brother to go to war with Troy so that he might have his vengeance. Agamemnon agrees, although more because taking down Troy will help his world domination bid than anything else.
Also, working the Greek pantheon into the film, who were major characters in the Iliad, would be extremely challenging. Even if there was a way to not make them too hokey or campy, it would mean making room to develop even more characters in a story that already has a keister-load of them as it is. So yeah, I'm all for the "realistic take on the legend" type of film they seemed to be going for here, rather than a literal adaptation of the Iliad.