No authority, except virtue
D&C Section 121 is a greater and more far reaching statement on authority than many know. It reveals essentially, what any person already intrinsically knows -- there is no authority, except virtue. It agrees with the Thomas Jefferson's statement on Natural Aristocracy. No man is required to follow another. The righteous will seek virtue at the hands of those on whom they discern have value to offer.
Part of the greatness of the beginning of America, was the abandonment of Gentile forms of church government and the great Democratization of Christianity wherein men realized they had access to God himself and were accountable to none but Him.
Nephi's great thesis on the Fulness of the Gospel relates how men are cursed for relying on other men, but they must rely on God alone. Other men may assist only as they are influenced directly by God himself, otherwise they have no authority, despite what office they may hold.
America started the democratization of worship.
The Book of Mormon affirms it.
D&C 121 affirms the democratization of authority.
Truly God is no respecter of persons.