So it is “demonstrably wrong” that she left the governor’s office after only two years? I think not.
No, it’s demonstrably wrong that it’s an impediment.
Just in case you missed the numerous posts on the subject, nineteen ethics complaints were filed right around the time she was chosen as McCain’s running mate (interesting timing, that). The pile-on cost both her family and the State of Alaska lots of time and money (http://www.adn.com/2009/06/21/838912/ethics-complaints-filed-against.html), more than she thought was fair to her loved ones and to the Alaskan taxpayers, particularly since the vast majority were dismissed. Oh, and several of the complaints were from one Republican activist alone.
Unlike presidents, governors don’t get much protection from lawsuits, and so she decided she could leave Alaska in her similarly-minded lieutenant governor’s unencumbered hands, and spare Alaskans further melodrama and interruption of the governance that needed attention.