Why is it important to determine criteria and interview questions before bringing someone in for an interview? Why are those in HR, the managers, and others doing the interviews so ill-prepared? No research needed, this one is an opinion.

A different F500 company (companies, actually) posts job openings for positions that: 

a) already have an internal/preferred candidate

b) are not intended to be filled, 

c) are posted to maintain the image that the company is hiring

d) were filled but the posting wasn't removed

e) a sloppy list of other questionable items as it pertains to the ethics of posting openings.  

CLEARLY, there's a problem with the ethics of Leadership and/or HR leadership.  How can these ethical violations be stopped?