I've been thinking on and off why the Lord would have a covenant people. I don't see the reason sometimes since anyone can become converted to the Gospel.
Following their events and God's relation to them mirrors, over time, how God treats someone who has made those covenants. So the span of history for a people would be equal to one person's lifetime.
From that point-of-view, a lot of actions make sense. When we are stubborn, the Lord removes the priesthood, and gives us simple laws to follow; strict guidelines to keep us in place (the law of Moses). We are also consigned to wander in the wilderness for a while, with only the Holy Ghost to guide us. Also, the promised land is the celestial kingdom. If we are faithful and obedient, we will eat the good of the land.