If history merely loops, you live your life over and over. Now Hurley would have been Jacob, but running things differnetly. The FST would have happened AFTER the OT (which it did in its own way). Hurly used different rules, was wiling to be involved in the world, making it a better place, and calling his candidates at the last minute instead of ruining their whole lives. They would have been drawn to get on a plane, which crashes on the island but this time with Hurley at the helm looking for his replacement, and each candidate take one of the turns for forever, rotating, so in each case the light is protected, at least, and ideally used for good. The way Jacob ran it then becomes a metaphor for the screwed up way we've run the world the last 2000 years, and a metaphor for a better way we'd like to run it.
PS: this is one of several