I believe it was an attempt to gather a headline rather than keeping the bigger picture in mind. Cheney is more than likely largely proud of the achievements of the administration, and his Commander in Chief. Memoirs are going to expose "woulda coulda, shoulda" aspects because we are dealing with individuals who are passionate participants in public service who probably had severe disagreements with colleagues and superiors. Second of all, this is also more evidence that the relationship between the Vice President and the President surpassed the ridiculous tale of Fool and Conspiring Evil Man.
It will be another useful (though flawed) tool for future historians to figure out to an even greater degree the complicated atmosphere of the George W. Bush administration.