Probably because there's little or not enough love to go around these days. Lol. But come to think of it, there's actually alot of divorce cases recently and although I haven't experienced divorce before I think i can relate to some of the reason which can be blamed on selfish desires, lack of trust and above all, impatience.
Selfish desires is probably one of the major reason for divorce as it can be broken down to cheating. The habit of not satisfying yourself with what you have and needing what's not meant for you especially in a marriage is one too common behavior that leads to cheating and eventually divorce. The same goes for lack of trusting your partner and always allowing minor or unreasonable suspicions come in between.
Another common reason and most important aspect of marriage that every couple should employ is patience. No two persons are the same and as such there's always going to conflicts and disagreements in behavior and other ways of execution self morality. If you can't find it in you to be patient and try to endure the other person's bad habits, you'll get a divorce everytime you get minor irritation from your new married partner.