As to your point, I don't agree that being governor is an automatic qualification to be President. Sarah Palin was a governor. Scott Walker just seems like a career political hack. Maybe he's really knowledgeable, thoughtful and intelligent. I'm no expert on Scott Walker, but being governor of Wisconsin isn't all you need to know about his background to judge him.
Sarah Palin's problem wasn't her resume, it was that her "job interview" was a total disaster. On paper without opening her mouth, she appeared reasonably qualified. I'm not saying being a governor automatically makes one qualified to be president, but it's sufficient reason to not throw out the resume before an interview.