In the ideal society, all citizens are equal in rights and privileges. But we don't live in a perfect society, and so we have public servants: citizens who have

In the ideal society, all citizens are equal in rights and privileges. But we don't live in a perfect society, and so we have public servants: citizens who have more rights than other citizens (eg. blowing through a red light without repercussions for a police officer) in the intent of them using those extra rights for the benefit of society. This is a tremendous privilege; it cannot come for free. It comes at the price of being open to any and all forms of criticisms (public and private) from other citizens, whether this criticism is in the form of a polite letter or a middle finger. You could try to legislate that only "constructive criticisms" are to be tolerated, but that's a very slippery slope towards a police state. The cost of allowing citizens to call officers "assholes" is one that we absolutely want to take on.