A LOT of people stay, or become, religious for spiritual growth. They study religious texts to become better people.
When Cardinal Sean P. O’Malley refuses to listen to a prominent Catholic leader speaking at a commencement because he disagrees with his stance on abortion, that is the opposite of spiritual growth. When O’Malley refuses to let a prominent Austrian priest speak at a parish because he disagrees with his desire to allow women to be priests, or for priests to marry, that is also the opposite of spiritual growth.
Ethics don’t spring whole from doctrine; they evolve as the result of debate and courage. With O’Malley, we don't get courage, and we don’t get spiritual growth. We get doctrine. That might have worked once, but today people who are seeking spiritual growth are also those who are fleeing doctrine and superstition. No wonder the church is shrinking.