Well, if you read the whole instruction, which can be found here: http://www.papalencyclicals.net/John23/j23religios.htm ,
there are many things to look for in weeding out bad priestly candidates.
Priests are not called to be “normal”, but to a level of perfection that seems odd to the world. The grain of wheat that falls to the ground and dies...to yield a hundred fold.
Normal fatherhood is all consuming, not sure where the time and energy would come from to address the needs of the flock? Obviously the ideal is celibacy.
But it is interesting how gays delight in blaming celibacy for the things they have caused.
I can appreciate that, but there's another view that says that the role of a leader is to "equip the saints" for the work of the ministry.
In other words, the pastor shouldn't be doing everything, he should be training others to do a lot of it.
It also seems odd to me that the idea "perfection" involves NOT having a wife and children.
Paul also said: "If anyone does not know how to manage his own family, how can he take care of God's church?"