I would have to say that the media plays the largest role here.
Very few statewide media outlets exist, so governors are likely to escape a lot of criticism because the opposing party often has no megaphone for it.
Your cable and network news stations tend to only focus on national stories while local media focuses on local issues, statewide perspectives are often left out.
So does this prove how ignorant most people are about politics? Do people really need to be primed by media outlets to like or dislike their elected officials?
