The novel
One of the timelines in my novel Quantum Cannibals is set in a post-modern city where everything is relative, and almost all behavior is acceptable. The police act primarily as psychologists, with the right to summarily execute people. It’s a society where intolerance is a capital crime, where the unthinkable became normal. Is that where we’re headed?
Our non-fictional world
Divorce used to be considered evil in non-fictional America, to be used only as a last resort. Today fifty percent of marriages end in divorce. Fifty years ago it was less than one percent. The unthinkable became normal.
As a corollary, twenty-five percent of American children live in single-parent households. Sixty years ago it was nine percent. There is a clear connection between doing poorly in school and living with only one parent.
The common term for men who dressed as or pretended to be women used to be “perverts.” Now RuPaul has his own mainstream television series. If you don’t praise 
“trans rights,” you get canceled. The unthinkable became normal.
Armed robbery, drug dealing, or theft usually lead to serious criminal charges and jail time. Alvin Bragg, the new District Attorney for Manhattan has announced it won’t seek jail time for anything short of murder or deadly assault. If this trend catches on like the “defund the police” movement did, theft and violence won’t be high-risk projects. Look at the crime rate in just about any major U.S. city. The unthinkable became normal.
Although adults having sex with children was common in some ancient civilizations, it is mostly taboo in
contemporary western society. Mostly? A reputable psychologist placed foster children with pedophiles for thirty years, all with German government approval. The beat poet Allen Ginsberg promoted the North American Man-Boy Love Association (NAMBLA). An academic press published a scholarly book promoting intergenerational sex.
From criminal to conventional
Homosexuality used to be a serious crime. Armed robbery, carjackings, assault used to be serious. Single motherhood, divorce, were frowned upon. Slavery was ubiquitous throughout the world. Women were property, considered too dumb to vote. Murdering Jews and other lower forms of human life wasn’t a crime… As the poet-pederast Allen Ginsberg said:
I don’t think there is any truth. There are only points of view.
Progress
We’ve gotten better at some things. Although Kinsey’s fake research played a large part in contemporary acceptance of homosexuality, it doesn’t invalidate the change in attitudes. But how far do we take it? If a lesbian is sexually harassed by a trans “woman” she considers a man, is the lesbian being intolerant?
What about NAMBLA? Are we going to be cool with man-boy love?
In the 1960’s civil rights activists were murdered by racists, sometimes by authorities. We remember and eulogize them. Now when the authorities kill violent criminals, we lionize the criminals.
Some old boundaries deserve to be smashed. But that doesn’t mean all boundaries, whether ethical, legal or physical have to go. A world in which everything once unthinkable became normal, would not be livable.
Things change. Back and forth, sometimes. Single parenthood may have troughed sixty years ago because of the peculiar circumstances of the post-WWII economic boom and the baby boom. But a century earlier:
“The picture described by Katz (1975:255) of the married persons in the different age categories who became widowed between 1851 and 1861 in Hamilton, Ontario, substantiates his statement that widowhood was “a frequent experience.” One out of four women and one out of ten men between the ages of 40-49 in 1851 were widowed by 1861, and the percentages increased to 34 for women and 15 for men at ages 50-59, and 54 for women and 32 for men who were 60-69 years of age. When marriage breakup due to the death of a spouse was combined with that due to desertion (which fluctuated with economic conditions), it undoubtedly affected at least proportionately as many children as a combination of divorce, death, and desertion did in the 1970s.”
I have seen similar claims for the number of single mothers in Montreal’s working class neighbourhoods around the turn of the 20th century. If there were fewer single parents in the post-WWII era, that may have been a progress. The question is who paid for it? Women forced out of the workforce after WWII? Society’s determination to offer greater job stability to wage earners through various social and economic measures, discouraging company takeovers for the sole gain of shareholders or encouraging unions?
The issue is whether one is a single parent by choice (eg. unprotected sex) or by circumstance, such as you present.
Unlike you, I think divorce helps millions to lead happier lives.
Unlike you, I have no problem at all with homosexuality and sexual diversity.
I draw the line at children being regarded as sexual objects, because a sexual relationship must be fully volitional, and children under the age of consent cannot be volitional sexual partners. Sexual relations with minors are essentially relations of power, not of equal partnership.
I draw the line at human-animal sexual relationships as well.
It is a reductionist approach to ascribe complex social phenomena to single social “causes”.