I think this is a thing that is actually changing in the recent decades. It used to be that marriages were more about connecting families, securing deals and even state issues (and so it still is in some parts of the world). Nowadays in Western society, marriages tend to be more about two people and their decision. But we're not 100% in the latter model yet, there's lot of social and legal baggage around the older ways. Divorces are not illegal, but they're still socially stigmatized.

The point is, we have to deal with how things are actually now, and not only with how they may/should be.