Perhaps for the exact reason you are implying - lack of respect for the judge and/or process.

People don't go to court because they "respect" the judicial process or the judge - they go because they are compelled by force or threats of force/imprisonment.

That said... it seems foolish to disrespect the judge, not because he/she deserves respect, but because they can abuse their power and punish you over slights to their ego. It's the same reason you don't run your mouth at a cop during a traffic stop - they would likely wield their small authority over you in a way that you found unpleasant.