I've come around to the conclusion that the "cognitive elite" (for want of a better term) underestimate the degree of social support and collective reinforcement normal people need to make good life decisions. They themselves continue to raise their kids in two-person households, etc. See: https://www.pewresearch.org/fact-tank/2015/12/04/education-a.... But they've helped chip away at the culture around monogamy, marriage, churchgoing, etc., because they themselves don't need those things to help them make good decisions.

It's like being overweight. Everyone knows what they should do. Most people can't do it, however, and there isn't much social support for it. In Asian culture, we have all of this social reinforcement about our weight and eating habits. (Though south asians differ quite dramatically from east asians with respect to what they consider fat.) In the U.S., you're left to fend for yourself. Some people go to the gym regularly and eat healthy despite all of the cultural forces working against those good decisions. But most people don't. They just get fat.