One reason ordinary priests of a diocese were required to be celibate (i.e., unmarried) was to prevent them from passing church livings and property onto family members.
Members of religious orders were (and are) required to take vows of Celibacy AND Chastity. Maidenly modesty forbids further public exposition of the point.
When married Lutheran and Anglican clergy become Catholic priests, they are of course, allowed to keep their wives.
This rationale for celibacy no longer exists.