"Judicial" catches them red-handed, taking the law into their own hands. Especially when they make in-house decisions on criminal matters, namely CSA cases.
But the other aspect is that it describes a parallel legal system that punishes people for "crimes" that are often seen as innocuous by governments.
Committee of Elders doesn't sound any kinder to my ear, but if they tried something different like "Committee of Investigation" or something similar, it would still have that fake legal ring to it.
Of course, they could drop the pretense of being God's police and simply have a chat with someone who stumbles and ask them to try not to do it again.
But the ones at the top love having a say in the minutiae of the day to day lives of the congregants. This is the system created by Rutherford, Knorr and weaponised by Jaracz. It's a bed that the current GB have to lie in.
You'll note that their instinct is not to wind back the harsh system, it is to disguise it and try to hide it from the eyes of prying governments.