They represent the political opinion of people who are affiliated with them. Once you getting involved in organizations that have a clear and defined political agenda; your whole argument that "nothing you do would ever be politically oriented" and that you are "fully neutral in all situation" becomes incredibly weak.

I am sure some "juge d'instruction" try their very best to be as neutral as possible. Some ostensibly aren't even giving this a flying fuck but both are repeating the same "we are non-political" any time they get the chance. When I hear this, I am unable to know if the person if of the first kind or the second kind. There seems to be 0 investigation internally to weed out the liars which thus casts shadow on the entire profession.

Trust is hard-earned, easily lost, and difficult to reestablish. This scandal touched the very essence of the French judicial system, yet had no major repercussion on the internal organization and processes of those "Juges d'Instruction". It's just business as usual. So until they come up with new systems to ensure better attempt at neutrality and they remove the people that have obviously been plaguing the system for years, it's normal and healthy that any mention of "neutrality" is immediately met with heavy skepticism.