Resumes do show what work experience people have, but they do not show many other things like if these people were doing work or sitting on facebook all day. What kind of person they are and if they are willing to work as a team. Teams at most jobs are important, and when you get one person that does not want to work as a team it could be difficult to do your job.
Interviews are where people should really let out their true colors. If you are willing to go the extra mile for your job and really care about your job let them know. Do not be scared to say how you really feel because most of the time that is what they are looking to hear not the typical answer they hear all day long. Bosses should look past the resume and what is written down on paper because it could look good when it is on paper but then as soon as they are hired they will show you what kind of worker and per truely son they are.