If you agree that the call to priesthood is from God is true and if one rejects that truth, then one chooses not to accept a basic teaching of the Catholic Church while accepting others. That's what I believe a "Cafeteria Catholic" to be. Who decides the hierarchy of truths? There is one truth i.e. Jesus Christ. It is for all of us to live in the FULLNESS of that truth.
Read some of Cardinal Avery Dulles' works. He has described the "hierarchy of truths" quite well, and this view has never been challenged by the Vatican.