The only saving grace for our Iraqi character is that he clung to some form of personal honor to stave off the normal hatred of American eyes upon him. Those who mistrusted him did not know his back story (he never really shared the full extent of his deeds, and his own betrayal of his people by working with the American military). It was probably that guilt that led him into personal martyrdom. He could never be happy and he made it so. That is why he was obsessed with a woman he could never have, Nadia (and some would say that was because she was truly gone - - - tortured to death by his own hand.) That is why Sayid is the saddest character on the show.
He could have set a different path for himself. But he was consumed by his own personal wrought of having been controlled by so many other people that his actions became involuntary and sick. He hated himself for being himself. He knew what he was, and made that fact an excuse to keep other people at bay. When things got tough at the beginning of the castaways survival period, after confrontation, Sayid retreated to the jungle alone. He was captured by Rousseau, another bitter survivor of her own war with the island. The irony is that Rousseau's torture made Sayid realize how sad Rousseau was in clinging to a hope that she could never attain.
It seems fate had dealt Rousseau and Sayid the same conclusion: that if they were reunited with their true love (Alex and Nadia), those precious objects of affection would be cruelly taken away.
So it was his destiny to be a sad, lonely man.
On the island he gained the respect of a few people, including Jack, because Sayid had an unbelievable array of paramilitary talents. But he never really gained a strong friendship among the main characters. His cold demeanor probably influenced his time with the other castaways.
He knew he was a ticking time bomb. In the time flash arc, it was his savage state that burst on the scene when he shot (and presumably) killed young Ben. But that action had the unintended consequences of turning young, island reincarnated Ben into the monster that Sayid loathed and shot.
When Sayid himself was shot in the ironic island circle of life, he was taken to the temple just as Alpert had done with young Ben. In the temple waters, Sayid was reincarnated as an evil being. He struggled with it but knew it was his true self. He followed Flocke on his rampage of candidate murder, until Sayid decided to give up.
Sayid had a sad and useless ending on his island story. For a man with major military intelligence, taking the time bomb down the submarine corridor and NOT sealing the various hatch compartments was a serious lapse in common sense and the cause of his suicide. As a result, the entire ship was lost, including Sun and Jin.
Even in the finale, Sayid comes across with a sad result. He is paired not with Nadia, but with Shannon, a rich bitch manipulator for whom he had only a short island affair. If that was Sayid's only true love with a real woman, than that is very sad indeed. And no man on Earth could stand spending any amount of real time with the selfish and petty Shannon - - - so it is also sad that Sayid was cast to live in eternity with her.
