One possible risk that I can see in married priests is that this might be the beginning of there being families and dynasties of priests. In Hinduism this has happened to some extent with the priests setting themselves off as a caste unto themselves which it is very difficult to get into if not by birth. If you want priests to continue to be of the people and for the people, they must continue to come from the people.
You may think, that’s not really comparable. Surely, anybody who is baptised and confirned a Catholic can apply to go to a seminary, and candidates are selected there on personal merits. But imagine a mediocre candidate having a distinguished priest or a bishop or even a pope as a father. Will the director of the seminary be able to turn that young man away? There is a risk he would sign him on to avoid friction with his superiors, and turn down a better but less distinguished candidate in his place. And thus starts the thin edge of the wedge.