Palin's vision of politics is so profoundly radical that even performing the duties of office becomes unimportant. The job you sought is no longer the point. It's all about the performance. It's politics as Conceptual Art.
Palin expects no one to wonder why in the world she would step down from the governorship, which is the only platform from which she can claim any political legitimacy. And we're not supposed to speculate? Come now.