I don't agree that people divorce because they didn't marry for love.
I agree that there are people that marry for other reasons but marrying for love doesn't mean the marriage can't fail.
A lot of things can cause a marriage to end in divorce. It could be that they feel out of love with each other, or things just didn't work out. It may be poor communication, infidelity, the nature of the job, domestic violence, etc. A lot of different things.
Aside from the effect that divorce has on kids, I don't see anything wrong with ending a marriage. If you're no longer happy in the marriage I don't see a point to continue if you both feel there's no way to work things out.
I can't advise a lady that is always been beaten by her husband to remain in that marriage simply because marriage is a union or whatever. Sometimes the best solution to a problem is to work away.