When you think about it this way it starts to make some sort of sense (or make your head spin).
Bush, or people in the administration, know more about the mistakes they've made than Kerry will when he takes office.
So, given that, doesn't it make more sense to let the people who made the mistakes carry on and fix them up? Who knows more about the fuck-ups than the people who fucked it up?!
Steady leadership in times of change.