As a counter point, on my grand jury only one or two people even wanted to be foreman, and neither were viewed as "knowing what they were talking about", since election happens on day one and no one really knows anyone else at that point. Civil cases may be different but I don't get the general impression lots of people are vying for the job. It may be a case of adverse selection: anyone angling to be foreman probably shouldn't be made foreman :)