I think priests would be better at their jobs, too, if they were experiencing first-hand some of the things others are dealing with in their sexual relationships. Inability to overcome in sexual relationships is what causes a lot of breakdown in marriage and, thus, social problems IMO.
A faithful priest IS strong in self-discipline; he HAS to be to live his celibate life. He can only get that from continual prayer on his part, and on OUR part, as his parishoners.
As for dealing with problems in marriages, the priest hears more about sexual problems, as well as all other problems, than almost anyone else on the planet, except possibly marriage counselors. He can provide an unbiased 'third party' to whom couples can go, as individuals, and believe that he's not taking the side of the other party.