I think that to answer fundamental questions like this, we have to step WAY back and examine the meaning of some of the most basic assumptions about life, family, and societies.
There`s a reason that having a Life Plan is right at the start of the Sloan brothers` 10 steps to starting a business. It`s because too many people, these days, have forgotten what life is all about, what it`s supposed to be all about.
Take a look at the way you`ve outlined the problem. It begins with a set of assumptions, and I think we have to question those assumptions. It also doesn`t address one of the most basic questions: what`s the meaning of a marriage?
Speaking very generally, a marriage can be viewed in two broad categories. The one type of marriage is two people coming together for no particular reason, but who feel strongly drawn to each other. That`s a feelings-based marriage. They shouldn`t be overly criticized because centuries of art and literature portray "love" as the essential reason for marriage.
But the other type of marriage, also with centuries of backing and wisdom, is where two people come together for a purpose. It`s a way to combine resources to reach goals. That`s a values-based marriage.
We all know about political marriages, and we know about arranged marriages. But in our oh-so-modern culture, we "feel" that they`re far from optimal. Then we don`t understand why we can`t "think" our way out of a seeming paradox.
Following the first type of marriage, it`s almost inevitable that the results will be exactly what your friends or associates have discovered. Two people working separately, each with their own life goals, neither of whom are willing to or are interested in using the marriage to any purpose.
It`s only in the latter type of marriage that the couple and family can even begin to work out a strategy for branching out into something entirely different from traditional workaday "rules."