Today in First World industrial societies, couples just try to wing it, moving out from the parents' house as soon as economically possible, living in a tiny nuclear household, sometimes very far away from the parents, and few humble themselves enough to try counseling.
My wife and I have been getting couples counseling on and off since before we were married, and it's helped a lot in learning how to communicate. Those knock-down, drag out fights are today a distant memory and instead we try to focus on communicating our needs, on expressing our feelings in a non-confrontational manner, etc. I'm all for more couples counseling.
Kids help, too. My amateur theory is that fundamentally speaking a couple is supposed to have kids. It's what we were designed to do. Kids are inconvenient and expensive and people mistakenly feel they'll have a happier life without them, but in a certain sense it's an empty life.
Some people probably should not raise kids, but the majority probably should, but also should learn better communication and then they will have a healthier relationship with both their spouse and their children.
Just my humble opinions :)