Perhaps if you had read any meaningful or substantive theology books--instead of Ray Brown, Charlie Curran, Hans Kung and the like you might know the answer to your very question.

The Church is called the "Bride of Christ" and "She" because the Church is a women. The priest represents the Bridegroom Christ to his Bride the Church. Christ is male, the Church is female--therefore the priest must be male.  The Mass is analogous to a wedding feast--but it is the wedding feast of the Lamb. The servers are analogous to the groomsmen at a wedding which is why they were traditionally male. A priest when celebrating Mass is not acting as a member of the baptized, but as the head of the body, as Christ is head of the body. 

The larger point I want to make is that the debate about women priests is as much a debate as to the nature of the priesthood as it is who can exercise it.  Those who support women's ordination tend to have a Protestantized notion of ministry. 

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