I doubt it is a coincidence that many of the best written contributions from the Christian tradition have been mystics. Christian mystics have, after all, always advocated for the deep and innate need of man to know the heart of God. And as Henri Nouwen (a recently deceased contemplative who impacted many, to say the least) so aptly put it, “To know the heart of God, is to know God.”
So what, you might add. Well, even the broadest Christian tradition holds to the tenet that human kind was made in God’s image. In my own round about thinking this would indicate that someone who knows the heart of God, or knows God, would understand humankind extremely well. (An aside: Even if you held that God was a construct of humans, knowing this construct would still inform you mightily about the nature and motivations of the humans that devised it.)
The contemplative lifestyle of the mystics robbed them not one bit of their understanding of human relationship and human nature. On the contrary, the often communal and contemplative lifestyle of the mystics has always contributed profoundly to their deep knowledge and understanding of all things human. In a place of deep union with God mystics come away with a loving and compassionate, yet shrewd, heart toward humankind — the heart God shares with us the more we come to know him.
And it is this heart, this understanding of the mystic, that continues to contribute so much to our body of written works. Sometimes the best way to understand (and thus communicate insightfully) the actions of people is to shed the numerous assertions those actions continually make on us, and to instead seek out the One who set them all in motion.