Very good episode. Definitely better than the Temple arc. I loved the deconstruction of the mythology (I usually do). The "guardianship" of the island exists not to protect the island per se, but the pockets of exotic matter contained therein--because proximity to the pockets heals and prolongs life, and close contact with the matter separates the consciousness from the body*. Jacob's Fake Mother, operating in a pre-modern paradigm, interprets this phenomenon in a religious or philosophical context. Jacob knows only that it turned his brother into Smokey, so he interprets it as a threat that must be contained. The Dharma Initiative interprets it scientifically, as exotic matter that breaks the rules of space and time, and digs up the Orchid well. So Jacob orders the Others to purge the DI. But to Smokey, it's nothing more than a shortcut home.
Now, Smokey's home isn't any particular place. We've known since he visited Jack off-island that he can travel to different places. His home has to be a different time, as well. Among his native people--perhaps even with his late mother. He intends to travel to the distant past, where he can live out the life his fake mother denied him. I suspect he never planned on taking the plane off the island; that was just a ruse to get the candidates to kill each other. He always intended to push the wheel. He built it, he knows how to operate it, he can control his exit point and emerge wherever--and whenever--he wants. He could take the plane, if only he had a Daniel Faraday to calculate a course that would put him when he wants to be. But he doesn't--unless he had Horace working on a special project out in his cabin all those years ago.
* The Man in Black's consciousness now animates the smoke. Desmond's consciousness played Pong through time when he discharged the Swan, and hopped through the multiverse when Widmore recreated that event. Juliet briefly became aware of the multiverse when she died after nuking the Swan site. Walt's consciousness traveled through time and space to manifest on the island as Taller Ghost Walt. The various other ghosts were separated from their bodies at the moment of death and got stuck on the island. The Man in Black can apparently leave the island and travel through space, at least to visit the candidates, so he must be temporally tethered--that's why he can't just push the wheel. He has to kill the guardian and the candidates to break that tether.
Now, Smokey's home isn't any particular place. We've known since he visited Jack off-island that he can travel to different places. His home has to be a different time, as well. Among his native people--perhaps even with his late mother. He intends to travel to the distant past, where he can live out the life his fake mother denied him. I suspect he never planned on taking the plane off the island; that was just a ruse to get the candidates to kill each other. He always intended to push the wheel. He built it, he knows how to operate it, he can control his exit point and emerge wherever--and whenever--he wants. He could take the plane, if only he had a Daniel Faraday to calculate a course that would put him when he wants to be. But he doesn't--unless he had Horace working on a special project out in his cabin all those years ago.
* The Man in Black's consciousness now animates the smoke. Desmond's consciousness played Pong through time when he discharged the Swan, and hopped through the multiverse when Widmore recreated that event. Juliet briefly became aware of the multiverse when she died after nuking the Swan site. Walt's consciousness traveled through time and space to manifest on the island as Taller Ghost Walt. The various other ghosts were separated from their bodies at the moment of death and got stuck on the island. The Man in Black can apparently leave the island and travel through space, at least to visit the candidates, so he must be temporally tethered--that's why he can't just push the wheel. He has to kill the guardian and the candidates to break that tether.