Juries can see the defendant and make judgments based on factors not important to the case
Not all defendants present themselves well and are judge negatively
Some defendants present themselves very well and are judged positively
Juries of private citizens do not know what they are doing
Juries are asked to make judgments on law they have little understanding of
Juries are not trained to ask the correct questions concerning how the lawyers conduct their cases (i.e. did the lawyers ask leading questions, important questions, questions that mattered to the case, etc.)
Juries make too many judgments based on gut feelings.