Instead of having grownups looking for stable, familial relationships, we have juveniles in adult bodies who're constantly chasing the heady euphoria of infatuation. Problem is that infatuation cannot be maintained. It's just not human nature. You'll become accustomed to the woman you stayed up all night thinking about during the first weeks of your relationship, and find yourself able to lie down right next to her and go right to sleep.
Insightful. I agree. It's the consequences of the Romantic philosophical movement, where childhood is revered and adulthood viewed as a fall from innocence (not consciously, in most people... heck, most people aren't self-aware at all, much less philosophical). Popular culture has bought into the basic tenets of Romanticism, and the consequences are legion, and very obvious in the eternal adolescents that surround us.
You may have something there. A friend of mine tells me his second marriage is on the rocks and he wants desperately to salvage it. His first wife wanted babies so bad she lost sight of everything else and moved to guys in when he went overseas, then demanded a divorce. He was ready to forgive her. Now his second wife, with whom he has two kids, says marriage just isn't as much "fun" as she thought.
I still think people should be held up to standards, mainly by setting their own standards of conduct high.