In bold relief, my own answer to the question is this:
Unlike other faculties, a seminary faculty is committed to both learning and spiritual formation.
They give themselves to the same level of academic rigor, but seminary faculty embrace a commitment abandoned a long time ago. The larger academy is neutral, if not negative about the existence of the divine. Seminaries are not, nor can they be. The study of religion without a commitment to the existence of the divine, never mind a specific construal of what God is all about, is the focus of university’s department of religious studies. In those settings the tools of understanding are philosophy, history, anthropology, psychology, and sociology. In a seminary, theology remains “the queen of the sciences.” The other disciplines amplify the seminary’s understanding of God, but they cannot replace it. For that reason, seminary faculties hold that it is not just possible to learn about God. It is actually possible to encounter God.
As such seminary faculty are “professors” not just of a subject area, but of a deep spiritual commitment.