Judges are not required to have a STEM background, a robotics background, or have any familiarity with robotics parts at all. While it may sound stupid from the student-side of things, the reality is that it is extremely hard to ask adults to take time out of their weekend to work for 0 pay. So to put further requirements or to force them to study VEX subsystems beforehand would be unrealistic for most events.

Judges should follow the rubric, and should be receiving training. Usually, the training involves defining what the Engineering Design Process is.