It's almost subversive, in fact. Paris is basically without merit - other than his appearance, he has no courage, no loyalty, no duty to his country, father or brother - he has no skill at arms, and only the inklings of remorse for what he's done. He has one brave moment when he offers to fight Menalaus to settle the matter ... but it's all undone when he publically shames himself and crawls to his brother's feet rather than die honorably. He sacrifices everything he has, plus his entire family and nation; "for love" Helen says.
Is that what we think of love? Is loving someone pretty so important, that we're willing to watch others die for it, but not die ourselves? Is Paris emblematic of the straying of our values, from honor and duty, to shallow obsession with appearances?
In the Iliad at least, Paris rides out every day with the Trojan army, and accounts for himself as an archer. He's not a hero like Hector, Ajax, Odysseus, or Achilles - but he at least knows that his life is as subject to risk as everyone else's. And for her part, Helen is far more ambiguous and nuanced - she is flat out abducted by Paris, who she comes to love because of the curse of the gods. But once he is dead, and Troy is burnt, she reconciles with Menelaus, who intends to kill her but can't, when he is struck with her beauty.
What does it say about us that in "Troy" (as opposed to the Iliad) Helen is not half as beautiful as the rest of the women in the cast, but the only blonde - and she is unambigously against the brave and fierce (but ugly) Menalaus, and unambigiously for the honorless and cowardly, but pretty - Paris?
Similarly, Berseis falls for the killer of her cousin, the slayer of many of her countrymen, Achilles. Why? He is kind to her - but his kindness is no more than she ought to expect from any Greek since she is cousin to the King of Troy. Unlike today - at that time respect for one's enemies was the norm, not the exception. That he saves her from depradations of other Greeks is... laudable, but perhaps not an adequate explanation for her throwing aside her people, her family, and her self-respect (not to mention her piety, since she is supposed to be a virgin servant of Apollo...). Why does she do it, other than that Achilles is pretty? Heck, he's not even a particularly skilled lover; strength of arms he may excel in, but when it comes to gettin' it on, he is not a man to be concerned with the pleasure of his partner, since he's apparently completely unacquainted with foreplay... in their big sexy scene, he basically just hops on her and commences the humping, without so much as a "by your leave".
Is the lesson to be learned from "Troy" that the best and only thing in life is to be with someone pretty? At all costs?