Well it is not merely a canon law doctrine, it is dogma as Saint John Paul II  and Pope Francis reiterated most recently the Church does not have the authority to ordain women as priests. 

In a sacramental view ordination is given to us by Christ as is, we can no more change it then we could use chocolate and cranberry juice for consecration. Ordination is a like the other sacraments is a mystery we receive but don't have any ownership of them. How can we presume that our desires are better than Christ's.  

Spiritual fatherhood and the priest acting in persona Christi as the vicar of the Bishop who in turn is a vicar of Christ is at the core of the idea of the sacramental priesthood. Christ incarnated as a man and chose male apostles, chose to address our relationship to God as that of a father and his children, this is not an arbitrary thing.

Christ is as a bridegroom, something which a woman cannot symbolize nor can she be a father. All our earthly relations are analogues.