People are in fact "attempting to get married for love" these days but are failing to appreciate the rarity of this beautiful condition.
Love does not break down as you say. That would be like me saying that a butterfly can return to its cocoon (sp?) or whatever. True love is irreversible, it becomes part of who you are and everything else becomes secondary.
Love does not allow a bad "business partner" to become a deal-breaker. It overcomes all odds, suffers all things, endures all things.
When you absolutely love your wife, your eyes may wander for a brief second at the lady who walks across the street or you may for a moment imagine what it would be like to have sex with a co-worker. That's your lustful flesh talking, not your heart.
Your heart is more than satisfied with the woman you love and who you would rather be intimate with than any other woman alive because she makes you happy in a way that no quickie ever could.