Paul Johnson, in his A History of Christianity, wrote that when Catholics were in power in Europe, the Protestants promoted and asked for tolerance, and when Protestants were in ascendance, then Catholics pleaded for tolerance. This dynamic is likely to appear in any power dynamic of that kind.
Moral subjectivism and cultural relativism were explicitly introduced to US elementary and high school students at least since the 1980s. Both concepts are nihilistic and destructive. Moral subjectivism asserts that morality is whatever anyone claims it is and that no one is right or wrong, per se. It is whatever you “feel.” This aligns with the distinctively American manner of speech where the speaker says “I feel that…” New Zealanders of my generation would instead say “I think that…” having not got so advanced in the therapeutic mindset at the time. If morality is whatever anyone says it is, then it is nothing. And, if cultures are immune from criticism the outside, then they are also worth ignoring, as Allan Bloom pointed out. Why learn about a culture if one is forbidden to evaluate it in any way?
It seems like moral and cultural relativism could thus be regarded as a kind of advance guard in a battle, designed to demoralize the enemy; a bland appeal to “tolerance” of any behavior, no matter how immoral. To every moral assertion the response could be “there’s no accounting for taste.” The implied nihilism cleared away any positive moral propositions – ones that actually were supposed to be significant. So, relativism was a kind of pleading for tolerance. Cultural relativism rendered out of bounds criticism of any other “culture,” such as Islamic cultures.
That was then. As a plea for tolerance, it suggests that common sense morality was still a significant factor, to a certain degree. Enough, at least, to warrant circumspection.
Relativism has now been replaced with a rigid Manichean division between the saved and the damned based on skin color. Far from subjectivism, there is absolutism and the scariest part of it is the epistemic hubris; the knowing with utter certainty the answers to all moral questions. Where for art thou, subjectivism? The only thing the two positions have in common is being utterly intellectually bankrupt. They both involve irresolvable contradictions rendering rational discussion impossible.