I am loathe to write this, in part because of the stink hole it nearly always leads towards. Yet it springs from something which is profoundly irritating and merits, indeed demands, refutation. I become almost instantly furious whenever anyone in trying to defend a position makes a statement either exactly, or very similar to, everything's subjective.
That is wrong on many counts. It is vapid. It is banal. It is trite. It is, I will say it, evil. And as subjectivity claims to hold the One Absolute Truth, namely that there is no truth, it is arrogant. It is, and I think this is the premier philosophic charge to be brought against it, intellectually dishonest. The person asserting it should almost always know better.
Yet they argue it, with passion and, well, finality. It is a tiring and endless assault to counter them. As Plato says, if you challenge them in detail they will simply continue to produce detail, and tie up the debate in useless nausea. They may get away with this tactic in the abstract, but in the concrete, in the world where we need to know what is actually true (was George Floyd murdered or not?), where there are actual facts to be gathered, analyzed, and from which are drawn true and just results, it is the realm of the charlatan.
Murder of course is an abstraction, and facts as facts are meaningless. In the realm of mere fact, all that happened in Minneapolis was that someone killed someone else. End of story. If you are going to argue that what happened was wrong, you must go beyond mere, hard fact.
Plato further teaches that if you challenge the subjectivists on principle they will merely assert there are no principles. Remember, they own the One Absolute Truth. But if all is subjective, and this is where the true intellectual dishonesty comes in, what exactly are they debating? What are they arguing for? How can even they know the One Absolute Truth is true?
I believe part of it lies in the idea that because there are different opinions among different peoples there cannot be one truth. The subjectivist argues an oversimplification: that the simple existence of differing points of view means all views are valid. They are confused about two things: one, that differences may come from a simple lack of understanding (and thus, if all involved are open to honest debate, truth can be found through conversation and logic) and two, that there are mistaken and sometimes evil people in the world who will create confusion merely to further their nefarious goals. Such people know the truth. Yet they actively seek to subvert it.
The subjectivist cannot, by definition, be arguing for any positive moral good because there can be no positive moral good in pure subjectivism. If all is subjective then no one thing is any more true or good or valuable than any one other. On that level, the murderer is equal to the one who dotingly cares for his ageing mother.
The case against subjectivity and subjective morality is so plain that I cannot imagine anyone really believes it. I think rather they talk themselves into believing it. Subjectivism of necessity involves deceit, and particularly self deceit. It involves lying to yourself, and, by easy extension, others. It involves the worst type of misleading: piping yourself and friends and family into the abyss of nothingness.
C. S. Lewis opined you will invariably find that the one who argues all is subjective most certainly holds beliefs which he does not think subjective. He wouldn't debate you otherwise. For the true subjectivist logically, when challenged, must respond to adverse opinion simply by conceding whatever point is at hand, because that belief, and again I stress subjectively, must be as good as his. In short, we really have nothing to discuss, and can only be left with a might makes right world. The stronger person, or the one who gets the drop on the other, gets his way. Or hers; whatever.
If there is no objectivity then there is no truth. And if there is no truth, all human acts are pointless. The only rational approach to our earthly condition, if all is subjective, is rank despair.