The sexual revolution was sweetened with the idea that people who love each other will be unhindered by needing to be married in order to express affection.
The assumption was - sex will still be a respectful act and will only make people happier and freer.
This quickly spiraled down into a push to desensitize sexual activity. Free sex would unhinge social shackles. If one feels disturbed that they crossed a line in their sexual behavior, the remedy for that was decidedly not to listen to one's feelings and put limits on one's behavior, but to quash these feelings by engaging in ever more free sex.
The assumption changed to - if you feel disturbed by promiscuity, someone brainwashed you to feel that.
The so called solution was to suppress your modesty, your boundary-feelings, the very feelings that should have alerted you to a crossed boundary.
Sexual repression was replaced with feeling repression.
The real solution is, in Jordan Petersen's words, "we have to be very very very careful with sex."
Chastity until a committed relationship is probably the best path.
Interfaith marriage was to reveal the underlying humanity among all people and jettison the shackles of religion when it came to limiting who one can marry. Jew should marry Christian, Catholics should loosen up about whether someone is in communion or outside communion.
The assumption was - you can intermarry interfaith and still have a strong family.
But this quickly spiraled down into family tensions and a creation of organizations devoted to supporting the intermarried, and ultimately tense, family situation.
The assumption changed from, you will still have a happy and stable family to: tension is a sign of intelligence.
Of course some intermarried families are harmonious, it depends upon the assumptions going into the marriage. I was witness to tension among supposed liberals.
The common thread in the above two examples is that the liberal weltanshaung transformed from an ideal of what can add to people's happiness.
People were not in fact happier.
And since they could not go back to how things were, returning to a chaste culture would be admitting sexual repression, returning to a conservative view of marriage would be an exclusive attitude, the underlying assumption changed to the following:
If you are too happy you will not be in a state of agitation in order to stage the next social revolution.
The pursuit of happiness itself was jettisoned.
As usual, the modern liberal lifestyle robs you of personal happiness that results from sexual limits and a strong family in order to goad you into bitterness and agitate socially.