One of the great strengths of an unmarried clergy is their availability.
The question of a married priesthood recently surfaced at the Synod of Bishops, held at the Vatican in October 2005. Curiously, the most serious criticisms of ordaining married men came from exponents of the Eastern Rite Churches, in which married priesthood is the norm.
Cardinal Nasrallah Pierre Sfeir, patriarch of the Maronites of Lebanon, said:
“Half of our diocesan priests are married. However, we must admit that the marriage of priests, even if resolving one problem, also creates other serious problems. A married priest has the duty of taking care of his wife and children, to ensure their education, to secure for them a certain social standing. The priesthood was also a means of social promotion in Lebanon. Another problem arises for a married priest, that of not having misunderstandings with the parishioners. Despite this, it can be the case that the bishop cannot transfer him, due to the impossibility of his family to move with him.”
It is precisely for the above reasons that the Maronite Catholic Church will not assign their married priests to a parishes in the diaspora. As Cardinal Sfeir also noted, matching a married priest and his family to a parish poses unique challenges. When things don't work out, it is far more costly to relocate the entire family than a celibate priest.
For a more personal and introspective understanding of this struggle, read this article from my bishop.
My experience of priestly celibacy in the Maronite Church in America
I'm honestly not suprised to hear that the Eastern Rite Bishops would be the strongest in their commentary.
They have the custom of married Clergy so have a much deeper understanding of how it dovetails into the Clerical life.
So few of us North Americans seem to have full idea of Theology of the Priesthood I would suspect there would be loads of confusion if the discipline were removed.
I've also noticed that most Catholics don't realize that the norm of daily Liturgy isn't a universal norm among Christians.