The majority is not always right, our parents are not always right, our teachers are not always right, our politicians are not always right, our justice is not always right, and established laws written and applied are not always right. Most people, intuitively understand this, just based upon the fact that there was a time when it was orthodox thought that the earth was flat, or that the earth was the center of the universe, or that blacks in America as ruled by the Supreme Court had "…no rights which the white man was bound to respect," and so on and so forth.
However, just because an established rule or law is wrong, doesn't mean that it is necessarily right or even appropriate to try to enlighten the rule makers or law makers of their error. In fact, doing so, depending upon how minority a position that one is in, could lead to one's death for heresy, blasphemy, being an enemy of the state, or whatever crimes that those in authority wish to paint an inconvenient dissenter with. That is why, children, even when they know that they are being dealt with unfairly or unjustly, and know for a certainty that their parents are materially wrong, are often careful not to assert that they are right, because the punishment is in all probability going to be worse, for the fact that they were insubordinate, disobedient, and rebellious, for it takes a big person to swallow their ego and thereby admit that they are wrong, when they have already gone on record that they are right.
The bottom line, is that while truth ultimately triumphs over falsehood, and right supersedes wrong, when those in power or in authority, are the very ones that adjudicate truth, falsehood, right, and wrong, then the end result is that all those that challenge those authorities for being wrong and false, are going to feel some real heat for exposing those in that authority for being wrong. This then means, somewhat unfortunately, that it isn't good enough to just be right, but rather that it is absolutely critical to win over influential others that are on the wrong side, to the acknowledgment that they should definitely consider amending their position, because, in many cases, numbers and voices working together, are the very things that matter most and are often mandatory to effect change.
To a very large extent, established law is unmovable, so to succinctly point out their errors isn't going to do much of anything, because established law actually doesn't care all that much about whether they are in the right or in the wrong, and even appealing to the better angels in established law's character, won't do much of anything either. What does matter, though, is getting enough people of influence and of power to move the needle in the direction that will overcome that wrong, and in order to do that, the prevailing sentiment must be won over in order for that to be accomplished. For, being right, when the established law is wrong, is a frustrating construct, because established law is much more about power, then the seeking for that which is right, and those that are in power and are in the wrong, will willingly cede little or nothing to those that are in the right.