Well, we do have to keep in mind that even resigning before her term was up left her with vastly more executive experience than the current Oval Office Occupant, and the MSM had no trouble at all fawning over his impeccable credentials as a leader and academic genius. Not that they seem to have ever gotten around to actually identifying any particulars of either one, but it all appears to mean someone who can claim to be Black without getting laughed at, who can speak regular English, and who has a college degree with no record of criminal convictions.
You actually have to delve into what was going on in Alaska with Ms. Palin 'way more than our "Aggressive, inquisitive, unbiased Press" ever would to understand why her decision made sense, but it did. She has very wisely chosen not to explain it in any great detail herself, since the eyes of the "Courageous reporters" would glaze over quickly and they would just end up mocking her if she did try.
The short version is that she was being systematically dogged by a campaign of successive ethics complaints over every step she took as Governor, which cost nothing for the complainants to make as 'Interested citizens' but which cost a great deal of time and money to defend under Alaska's unique ethics procedures. Any appearance in the lower 48 required a day's travel each way and would have only fueled the harassment campaign by taking time away from governing. She really had a choice between finishing her term but staying off the national stage to do so, or being a national player in the 2010 campaign.
I would have to say the results she achieved indicate she made the most beneficial choice for the country, if not for her personal chances to hold national office due to the dismissive and unexamined point of view the MSM took of her action. There is a huge amount of sexism in the MSM treatment of her, but like race, that apparently is only a bad thing if it's working against a Liberal.