There are several explanations, none of them pretty or complimentary. There are three main culprits: subjectivism, egalitarianism, and relativism.
Let us begin with relativism. Without critiquing Albert Einstein's General Theory of Relativity, that theory somehow infected the realm of thinking in the West. It was attractive to those who were critical of the West and its economic, technological, and scientific achievements. They were drawn to it like moths to a light bulb. Einstein's theory is an attempt to explain the relationship between gravity and entities with mass and the speed of light. However, there is something alluring about the term "relative" to cultural relativists, multiculturalists, ethical relativists, moral relativists, artistic relativists, and every other kind of relativist. It allows them to discard the Newtonian concepts of time, space, and gravity, to discard the concepts of sensory perception, objective reality, and reality itself. And especially of the volitional nature of man's mind. It allows them to dispense with absolutes, certainty, values and value measurement.
Relativism is the cowardly form of nihilism, whose end is to destroy man's cognition and his capacity to hold values by elevating the mediocre, the nondescript, and the irrational.
As Ellsworth Toohey, the arch villain of Ayn Rand's The Fountainhead, articulated the principal method:
"Don't set out to raze all shrines — you'll frighten men. Enshrine mediocrity — and the shrines are razed."
It is for the sake of the mediocre, the nondescript, and the average that the relativists have waged a constant and enervating war.
Subjectivism is the position that no opinion, statement, or observation is more valid (or truer) than another's. Truth, therefore, is "subjective," dependent on an individual's unique "perspective." Truth cannot be known for a certainty. An individual's perspective is governed and molded by his cultural "conditioning," or by his genes, or by his "class," or by his tribe or voting bloc. His "truth" is different from another individual's. His mind is but a passive receptor of things around him; he exercises no volition to judge and evaluate things. He is a reactor, not an actor.
Subjectivism is closely linked to egalitarianism, which asserts that, as with political equality, all values are of equal status and importance. All values are alike, and all distinguishing marks or measures applied to them are not only irrelevant, but even immoral, for they infer one value's superiority over another.
American lives and American treasure must be sacrificed to preserve the stagnant, filthy, mysticism-ruled cultures of Iraq, Afghanistan, Gaza and Egypt, because they have every "right" to exist as does America.
Palestinians have every right to hate Israel, because Israel is what they are not.
When you examine the relativists' arguments, you will see that truth has nothing to do with their concern for truth. Truth is thrown out the window in favor of some unprovable Platonic "form" because, their philosophical mentors have said, the things one sees are but rough, indistinct sketches of those things which exist in their "perfect" forms in another realm not discernible to our senses or which confounds them. Or, as an alternative, they are Kantian defined entities that have no relation to themselves or even to any other-worldly "forms," because, the Kantians say, our senses so totally warp our perception of things "as they really are" that what we see is nothing at all. According to Kant, our minds are pre-programmed and biased to process sensory data and to assign absurd and completely arbitrary labels to everything we see, hear, touch, or know, because we have this sinful urge to pretend we know things.
Any way we look at it, say the Platonists and the Kantians and their numerous academic and journalistic protégés, it's sheer, hubristic sophistry, and men ought to be mature enough to concede that they're nothing but miserable, shapeless forms of random matter with delusions of grandeur.
Consensus plays a role in this brand of relativism. The more people who believe in a certain, opinion, statement, or observation, the "truer" it must be, because so many people agree with it (or disagree with it, so it must be "not true"). This is the popular understanding of "truth." It raises the concept of "number" to the status of a golden calf or an extrasensory oracle in a trance to be worshipped and heeded and deferred to. Thus, "truth" is determined democratically, by majority rule, because numbers are imbued with some magical efficacy to make things true. Reality, it would appear, is susceptible to stuffed ballot boxes and governed by numerology wedded to astrology.
Reality says that the South Side Chicago criminal gang took care of the North Side gang by inviting them to a peace conference and to a share of the Detroit Purple Gang's stolen whiskey, but instead lined them up against a wall and machine-gunned them. The liberal/left multiculturalist fantasy world premise says it's Hamas showering Israel (now cast by Islamists and the Left as a gang) with harmless Fourth of July fireworks, then inviting Israel to a cease-fire and peace talks and a plate of halal cookies fresh from the U.S. and Egypt, and then shooting Iranian-made paint balls at the Israelis, swearing on a stack of Korans that Hamas means no harm.
The doyens of diversity claim that the political aspirations of terrorists, whose means of persuasion include murder and mayhem and destruction, are no less legitimate than those of Israelis, who live in relative freedom and are a productive nation, whom they also charge with murder, mayhem, and destruction. Western pragmatists (another species of relativist) state that Israelis have nothing to fear by being encircled by a Palestinian state and other Muslim states, or even living in a "One State" with millions of Muslim Rodney Kings who just "want to get along."
Reality says that any works by Jean-Léon Gerome, Lawrence Alma-Tadema, William-Adolphe Bouguereau, Daniel Chester French, or virtually any notable 19th century painter or sculptor (except Rodin, who was a kind of bridge between representational art and the abstract) is superior to anything produced in the 20th century by Warhol, Pollack, Picasso, Giacometti, etc. Relativist esthetic criticism says that no work of art is superior to another, because everyone sees things differently, it's all relative to one's culture or genes or class. Rodin's or Giacometti's "Walking Man" is just as good as Michelangelo's "David" or Frédéric Bartholdi's Statue of Liberty.
But relativists do not completely eschew measurement of values in any realm. For example, they would gain nothing by comparing a Kewpie Doll to a Hummel figurine, and claiming that they are of equal esthetic value (which, in fact, they are). What they need is a standard to muddy, sully, and obliterate, and would proceed to assert an esthetic equivalence between a Kewpie Doll and a statue of Leonidas, hero of Thermopylae. This is nihilism in action. Leonidas perishes; the Kewpie Doll survives.
Beauty, they say, is in the eyes of the beholder. But if the beholder doesn’t agree that something is beautiful, in modern culture he is free to spray paint it or take a hammer to it or cover it with a linguistic burqa lest it offend the subjective proclivities of other beholders.
Reality says that you are being of volitional consciousness who can think and make value judgments about what will advance your life and act to secure your happiness as a rational individual. The liberal/left fantasy view says that you are but a cog or a cipher of your class, race, tribe, gender, or group or social environment, a puppet of determinism helpless to be anything but what you are and to do whatever it is you do. Reason and rationality are simply "perspectives" no better or no more valid than psychosis or channeling the spirit of Eleanor Roosevelt or believing in witches or Hobbits or Muslim warlords who rode to heaven on white steeds to confer with Allah and the angels.
Reality is taking advantage of the First Amendment and saying anything one likes, as crudely or as elegantly as one wishes, without inviting legitimate charges of slander or libel, and accepting the rewards or the flack for having done so. Fantasy World First Amendment rights, however, must be policed to protect and preserve the feelings, dignity, self-esteem, and image of anyone who is slighted by the least amount of genuine or deserved criticism, particularly groups with political claims to victimhood and discrimination.
Thus, if one demonstrates that Islam and Muslims are out to conquer the world and establish a global caliphate, that proof is not protected by the First Amendment, and one can be harassed, shunned, marginalized, censored, sued or jailed. Muslims who noisily demonstrate in public streets and carry signs that say "Islam Will Dominate the World," and "Freedom of Speech Go to Hell," or establish a Facebook page dedicated to discussing how best to roast Jews and apostates, are protected, and are rewarded with continued welfare benefits and special accommodations and the sympathy of a press silenced its own unacknowledged brand of "Islamophobia."
The best method of bursting any relativist balloon discussed in this column is to inform the relativist: You are making an absolute statement. Isn't that against the rules? Aren’t you violating your own maxim? How can you be certain that what you're saying about relativism is true?
But few people realize how easy it is to correct the subjectivist, multiculturalist, or egalitarian. The sharp relativist will reply: How do you know it isn't true? It's then that you'll realize that the relativist is playing mind games with you, and that his chief end is to make you doubt the evidence of your senses, question the efficacy of your reason, and help him negate the supremacy of your values.
It's then that dialogue should end with the relativist, and it will be up to you to terminate it. Unless you are addicted to the sophistry of an intellectual Möbius strip.