Like I said, you really can't say unless you're in the situation. The problem with people is they always like to judge without knowing the circumstances. You WON'T know what is going on or how the person feels unless you are the person.
The problem with marriage is that people change. If you marry someone, they can be someone completely different in 5 years so you never really know who you're marrying. If the couple grows and matures in a way that is suitable for both parties, then it's good. However, that's not always the case.
For example, what if a couple got married. The husband is a social drinker who only consumes alcohol on special occasions. They're happy and in love. However, he loses his job after two years and although he tries his hardest to find a new job, he can't and his wife has to work. He feels worthless and thinks he's a failure. The only time he feels good is when he drinks too much. Unfortunately he gets violent when he drinks and when he comes home to his wife, he abuses her and threatens her.
Of course people can say that there's counseling and he can stop drinking and there's no need for a divorce, but you have to realize that no matter what, she can't FORCE him to stop drinking, he has to want to.
Marriage is not one sided. BOTH people have to want to make it work. If there's only one person who is concerned with making it work and the other wants to divorce, then is it FAIR to expect the person to wait around and simply HOPE the other will want to work on things SOMEDAY? So if the husband beats the wife or the wife is cheating on her husband with someone at the office, the other spouse should simply wait for the other one to realize they're harming the marriage? How long will that take?
Therefore, don't be so judgmental and shallow-minded. If you don't know the circumstances, you don't have the right to say anything.