In many failing relationships, a person behaves badly and then isn't accountable for that behavior or turns it back around on their spouse. So subsequently, the spouse who is working hard at keeping the relationship and not behaving badly is accused of nagging, overreacting, or other things that really aren't true. It's enough to make the spouse who isn't absent, controlling, abusive, lying, drinking, cheating, etc. feel a million shades of crazy. It’s a relief to end a marriage where an enabling personality has put up with things being turned back around on them by an unaccountable spouse.