After the pilot, the decision was made to "save" the character of Jack, and make him the leading man in the series.
In the leaked writer's guide, the character-centric sales pitch pictured Jack as follows:
Brave, sharp-witted, powerful and vulnerable, Jack finds himself cast in the role of hero whether he likes it or not... and he's more inclined to go with "not." Despite having shared a story centering on his time as a spinal surgeon and having clearly demonstrated his abilities as a doctor, much of Jack's past is shrouded in mystery. Simply put, it's not something he likes to talk about- but if he did, it would certainly explain his tattoos. Jack's reason for being in Australia is something he doesn't like to talk about either, but we come to learn he was heading back to the States for the funeral of someone who has long defined his path. As the series unfolds, our stories continue to find Jack as the one the other castaways call upon to make the life and death decisions they are unwilling to make for themselves.
The main writing points to this character:
Brave. We don't really see Jack as a "hero" brave, as his approach would be more conservative, studied in contrast with Locke's aggressive hunter stance.
Sharp-witted. We don't see Jack with any deep humor - - - the sharp tongue went to Sawyer, and the humorous diversions went to Hurley.
Powerful. It depends on what that means; Jack could fight hand to hand okay. He could have a powerful influence over some other castaways actions, but he did not get his way all the time.
Vulnerable. Most brave, sharp witted and powerful men do not show or act vulnerable. We learned early on that Jack did not want the spotlight, which is counter to what the people around him wanted to to do for them.
But there is a golden nugget in the summation which I had raised when the series originally aired on ABC. There was always a question of whether the characters we saw on the show were actually who they were shown to be; the question of whether they were representations, egos or transference like avatars was something most people feel uncomfortable to address. It would raise some doubt as to whether the island events were real or surreal.This hit home after the episode where Jack, as an adult, goes off to a beach in Thailand and hooks up with a mysterious woman.
We were lead to believe that following his marriage's collapse, Jack visited Thailand and started a relationship with Achara, a tattoo artist. She was drawn to him, but at the same time wanted to keep her distance from him. She said she saw him as a leader who, although strong, could also be unhappy. Jack insisted she tattoo him. The tattoo she designed translates to "He walks among us, but is not one of us."
However, there are other possibilities. One, is that Jack was never a surgeon. He was a rich kid who was supposed to be a great surgeon like his father, but he failed out of medical school. He got caught up in drugs and dreamed of the ideal life, but even in those dreams he could never meet the expectations of his father. He wound up wandering the world, landing in Thailand during a binge cycle. Two, is that Jack was a surgeon, but it was he, not his father, that butchered a patient on the operating room table. He mentally shifted the blame to his father, whose pressure to make him a doctor was something he did not want as a child. This notion of significant secret in Jack's past is contained in the guide's key sentence: HIS TIME AS A SPINAL SURGEON AND HAVING CLEARLY DEMONSTRATED HIS ABILITIES AS A DOCTOR, MUCH OF JACK'S PAST IS SHROUDED IN MYSTERY. It can be read in the PAST TENSE of being a surgeon. The mystery would be why he was no longer a surgeon - - - his fall from professional grace. Three, that Jack never had the chance to be a surgeon until he "arrived" at the island (if the island is a spiritual place, and Jack died on the schoolyard from the blow to the head during the bully fight. Since Jack never was able to grow up, his soul was lost in the fantasy of what his life could have been.)
We get a notion that Jack would be haunted by his father, but the island ghost was actually MIB/the smoke monster taking Jack's memories and using them against him. If the island was a psychological chamber, the connection between Jack's thoughts and actions could be as manipulated as those people forced to be re-educated in Dharma's Room 23. There is something deeply rooted in mind control, in all its forms - - - from peer pressure, to parental mandate, to social norms, to emotional abuse - - - that is a central theme to the show, the darkness in the characters story DNA.
In the chaos of the pilot, Jack did make life and death decisions - - - mostly to save one person, he lost another. But those decisions were random. It was when the other castaways started to make demands upon him, like Kate to let the Marshal die, that Jack suddenly retreated within himself. A surgeon has to have nerves of steel. A surgeon deals with life and death decisions every day. He should be used to it. He should be able to maintain his balance and cool to make intelligent decisions. But the idea that Jack could not cope with the pressure of these basic professional requirements again poses the question of whether Jack was really, truly, the great spinal cutter we think he was on the show. It would seem more telling that Jack as being the fallen doctor, hiding his great secret of his own deadly shortcomings (bad surgeon, drug addict, mental illness or combination of those traits) than putting him on a pedestal from the very beginning as being Mr. Perfect.
But quickly, Jack did not make decisions for anyone. It was clear that there was supposed to be some "order" in the new island community, rules so to speak, but it quickly devolved into every person for themselves. People did what they wanted to do. No one could order someone to do something they did not want to do. People could get along, but not pull together. That was the sense of beach camp. And that culture lead to no sense of urgency to do anything collectively, like systematically think of escape and rescue plans. Jack could not rally the group to any clear path. When he would return to the island, he gave up on trying to lead his fellow survivors - - - he was content on being a janitor, even though he was tired of trying to clean up other people's personal messes.