Even if there are children, if a couple can not get along in a civilized manner and definitely if there is any sort of abuse, alcoholism, or addiction, then the divorce is the better course. Of course there are times when one has to wait it out for practical reasons.
Although I do not advocate divorce, I do believe divorce might be better than a bad marriage, especially if there are children involved. Often in a bad marriage there is a lot of fighting and arguing, creating a very stressful household. It can be very confusing for kids and they can become "pawns" for fighting parents. A peaceful household is much better for children.