There are numerous creative implications that can exist in a work involving conversations as opposed to a work that is made up of a sole viewpoint. Using conversation, the author can develop different points of view, and can make a weighty argument. A work becomes more complex with each facet that is added, and each character adds possibilities to the storyline.
Conversation adds weight to a work that a work from just one viewpoint lacks.
Though the reader tends to lean one way or another, I feel both sides have strength.