A man with a homosexual orientation going into the priesthood is not sacrificing a wife and a family of his own, he is just refraining from activity that as a Christian and a Catholic he is not supposed to engage in anyway. You can't give up something you don't have a desire for. Also, the priest is supposed to be the icon of Christ the bridegroom married to the Church. If a man isn't capable of marriage how can he reflect this in a priestly vocation?