Software developers believe that documentation is just another way to say code is buggy. The reasoning is like this: If the code was easy to understand and/or did what you expected, then why document it?
While this is true at the level of a code line, there should be some documentation explaining your overall view of the world.
Next, we have end user documentation. End users have no idea how software works, they just know they have to get some work done. Stat. For them, good documentation can be the difference between a nice day and weeks of overtime.
- The Evolution Of User Manuals (forbes.com)