The vow of celibacy, that is. It only causes good men to ignore a call to the priesthood because they want a family, break their vows once they're there because God places their soul mate in their path, or enables a monster who wants to use the reputation of a man of God to put them beyond accusation when they rape children.
Not to mention, a priest who isn't married doesn't have the tools provided by personal experience to be a marriage counselor. It's like asking your maiden aunt about sex.
46 minutes ago