So what exactly is the point of the show?
At one point we are led to believe that Jacob and MIB are playing a philosophical game of chess with the human race. There have been many allusions to "it always ends the same" with a chance of "it only ends once." So what happens IF Jacob is right? What ends once? Anything? Shouldn't he have won by now by bringing the Losties back?
And then the question is, why? Is the V equation really correct? The world is going to end unless these people come to the island to stop it? And the world ending apparently is MIB escaping? If Jacob didn't win his game, the world would end? But how would MIB get off the island then?
Why does Jacob need a replacement? How does that factor into the game or the world-ending numbers scenario? And doesn't Jacob know that MIB is going to kill him at the exact time he finds his candidates? Why is Jacob ok with this?
And if the smoke monster was created arbitrarily at one point by Jacob, why does him leaving destroy the world? He literally is a person who just wants to get off the island and see where he came from.
I think I understand the logic on this one, that since he is merged with the light/magnet energy, if he takes it off the island it will somehow ruin everything, as alluded to by his mother. Maybe somehow people would try to harness this energy from him and it would cause everyone (such as leaders of countries) to go mad with greed trying to get this power, either from him or the source. Which is not instant extermination, but still, plausible by Mother's explanation of evil men's greed.
NONE OF THIS CRAP MAKES ANY SENSE.