I have been a program manager for a publisher for 15 years. My goal is to publish works of quality and not write them. I have encountered several authors who have stated that they need a map for their work, but it is not that important. Their point of view is that a map is only an afterthought and has no place in telling a story. Those authors have not been published.

I can name several examples on how important maps are to a story in several different media releases. These include:

The Fellowship of the Ring (any of the versions)
The Muppet movies (Travel by map)

The Lost Regiment by William R. Forstchen

Video Games
Star Trek (any of them)

Table top role playing games
Any adventure of campaign.

The list can go on and on of examples. There are two methods of storytelling. You can use the dialogue and passages of a story to tell it or show it. Both show a story and tell a story has their own merits, and I will not go into a debate on which is better. A Map allows you to do both at the same time. It allows the reader, player, viewer a point of reference for where the story is. It also allows the possible directions the story can go and some of the obstacles in each of the possible directions.

It allows the author of the story to use a visual tell / show aid to get their story across to their audience. I know I am passionate about mapping. I still remember getting my first professional cartographer credits from Steve Jackson Games. A Map should never be an afterthought of a story. It might come before, during or after the story is completed by it is an important part of the story or it should be.