BTW, I offered a similar argument to a judge a couple of years ago when was I considered to be a prospective juror. I asked to be excused because I question the credibility of the entire system, so I cannot make an honest decision regardless of what is presented as facts on the trial. The judge was not happy and gave me a lecture how people taking the system and their role in it seriously can improve it, but he nonetheless excused me.
Wojtek