Jesus knew his audience, and used a template people were able to understand and relate to at the time. I’ve yet to meet a Catholic priest who would tell you otherwise.
He called them "true children of their father, the devil" and "whitewashed sepulchers". He didn't give a flying hoot about cultural conventions.
Besides, priestesses were all over the ancient world; it was a common place. But never in Judaism, only in paganism.
Jesus' audience was worldwide and spans all time. His message isn't affected by the outlook of the people in a specific point in time. The 'template' He used worked because He was talking to His creation.
The theological support for the exclusively male presbyterate, however, is rooted in the continuous, unbroken tradition of the Church, east and west, which in turn is founded on the example of Christ in establishing the apostolic priesthood. Christ, who was so radical in breaking traditional Jewish customs, especially where women were concerned, yet chose only men for his apostles. Andit was not as if priestesses were unknown in the Roman World. Can we really say that he would stop short here and be bound by cultural conventions if he really thought that the dignity of women was implicated?
As John Paul II put it in Mulieris Dignitatem, "In calling only men as his Apostles, Christ acted in a completely free and sovereign manner. In doing so, he exercised the same freedom with which, in all his behavior, he emphasized the dignity and the vocation of women, without conforming to the prevailing customs and to the traditions sanctioned by the legislation of the time." This point was reaffirmed in Ordinatio Sacerdotalis, which treated the question as settled and part of the deposit of the faith.
The mistake, I think is in understanding the Church in purely material terms: and in material institutions, we are accustomed to the complete equality of men and women now. It must be said, in fairness, that many priests and bishops may be to blame to some extent by behaving in ways that make the priesthood look like a power institution rather than one of service - and ontological re-ordering.
2) Then there is the practical argument you seem to be making: We are short of priests. The Church is dying.
In this regard, however, I would affirm the point made by others: traditional, orthodox orders and dioceses which hold firm to doctrine and traditional charisms and practices are not having problems attracting vocations (male or female). The traditionalist orders FSSP and ICKSP literally have waiting lists because their seminaries are filled to capacity. In St. Louis, Kenrick Glennon seminary has doubled its seminarians (to well over 100) since Archbishop Burke was installed in 2005.
And it must be observed as well that mainline Protestant Churches (Episcopalians, Presbyterians, some Lutherans, some Methodists, etc.) which have ordained women are all losing membership, and often have vocational shortages. Clearly having ordained women has not solved their problems.
But I do agree that a significant number of American Catholics are open to women's ordination. If so, however, I would suggest that this is a measure of the degree to which they think as Americans, rather than as Catholics.
To paraphrase C.S. Lewis from above, what is striking about U.S. Catholic parishes today is that - priest notwithstanding - they are dominated by women. Too few men are involved. To make the Church even more feminine seems an unlikely way to bring them back in.