You are arguing from the general with a presumption it applies in the specific. You need to prove the specific. Even the Catechism paragraph you cite acknowledges this:
1579 All the ordained ministers of the Latin Church, with the exception of permanent deacons, are normally chosen from among men of faith who live a celibate life and who intend to remain celibate "for the sake of the kingdom of heaven."70...Apparently your understanding is different from the oath taken by priests during ordination. They are required to observe chastity.
The vow is voluntary because becoming a priest is voluntary.
ALL priests take the Oath of Holy Orders. That Oath contains the words above. How you can claim that celibacy is not required when the Oath of Holy Orders requires it?