I know this probably works and when described like that it sounds like a good idea. It seems basically you start with a single idea and write around it to make it bigger.

But, I also can't help but think of the dilbert cartoon where the PHB insists that the most important thing is the name of the project, before you even know what the project is.

Personally I think that there's some overlap here as both techniques seem to be trying to show how to start from a single idea and bring it into something more complete.