An interesting defense of software modeling on this post by Grady Booch:

a) the most important artifact of any software development organization is executable code and yet b) modeling is essential in constructing such executables. This is because c) models help us reason about, specify, construct, and document software-intensive systems at levels of abstraction that transcend source code (and the UML is the accepted open standard for doing so). That being said, it is a pragmatic reality that d) some models are essential (and should be retained) while others are simply scaffolding (and should be discarded).

Booch again:

Everything is a problem of classification.
Indeed, there are two kinds of people in this world: people who divide the world into two classes, and those who do not.