In having discussions we often might get kind of intellectual, academic and detached. Also, we might tend to guard our image and opinions, not wanting to look bad or appear uneducated.
A story is more experiential, telling what happened, what one did, what one thought, what one felt. It is not something to argue for or against, so therefore it might be more honest, giving a more true picture of what is going on.
Life is a process of discovery. We can't know exactly what to expect. However, when we have intellectual discussions we tend to pretend that we DO know how the world works and what can be expected. Therefore we spend a lot of energy defending positions we don't really have much right to hold, and we might miss the wonderous unfolding of life in front of us.
A story can show the process somebody goes through, rather than just the official results that can be defended publically.
A story can act as a metaphor that others can use. It will tend to activate sub-conscious parts of the reader, rather than just the analytical faculties.