They see the relationship as a business, that needs looked after and should grow successfully.
I know a couple who lives this way, and their parents too.
Modern women won't like it anyway: they'll want a "friend" to satisfy their sexual needs.
There is research suggesting that couples that work together (i.e. a family business) are less likely to divorces. This makes sense, as such couples have a common goal and high degree of interdependence. Similarly, couples that are raising children are less likely to get divorced. Again, they have a common purpose. Once the children grow up and the parents become empty nesters, the odds of divorce go up.
This is the case for many Italians, so many inherithed their businesses, but someone says that seying each other at work and at home too would make your relationship fail.
To me that just sound simple: if you and your wife work togheter in a family businesses, you have less exposurefor cheathing when your partner isn't there.
Also, the success is tied to the fact that everything the couples relies on, like financial, social stability it's in one unique place, and if you leave, you're actually in the street..
It's interesting to discuss more about this topic