In general, what’s difficult with fault as a way of getting a divorce?
All fault grounds are ways the legal system through its courts comes to term with a failed marriage, and this means that the law must reach inside a very intimate human relationship. This penetration puts extraordinary demands on courts and a judge, who not King Solomon.
Even when true, most fault grounds often happen when hopes and dreams go astray, and such legalistic incursions in the lives of flawed mortals are not the arenas where litigation is at its best. Adultery and extreme cruelty or cruel and inhuman treatment are symptoms of marriages that are troubled. Sexual desertion certainly is a indication of a marriage gone sour. Habitual drunkenness and drug addiction are really medical problems where a person needs help. By definition, these human problems do not yield well to legal intervention.
All fault grounds can, of course, be used to end a marriage in jurisdictions where they are the law, but all states now have less legally difficult, less expensive, less emotionally damaging ways to do it than a fight-to-the-death fault divorce.
Adultery, cruelty, abandonment, imprisonment, insanity, and drug or alcohol addiction are considered the offenses that make up grounds, as we have just seen. There are a few other grounds that are still found in some states: bigamy, impotence, child abuse, and "crimes against nature." It is up to the individual state legislatures and the courts to determine just what "crimes against nature" are.