I think you'll see that GNS tends to help design the type of games it has helped design. But there are more games on heaven and earth than dreamed of in your GNS theory Horatio.
I actually have a pet theory about this that I can't prove easily, but that I think makes a fair bit of sense.
People are different in the amount of abstraction and conceptualization they are comfortable with. Some people like things to be very concrete - we will be at place X at time Y, the job will require these 5 things, if I save $6/day for the next month I can afford to buy myself Z, etc. More abstract people like to leave things open, are more comfortable with improvisation, and tend to be more concerned with what they COULD do than what WILL happen.
I think that this personality trait has a direct correlation to the kinds of games you like to play. If you are a very concrete person, you probably want a coherent, inclusive ruleset that clearly defines what you can and cannot do, and it's doubtful that you want to play a story game with a skeleton ruleset and improvisation on the spot as a primary objective. On the other hand, if you like abstraction, a rule system where one roll can be made to resolve any type of conflict, and the focus of the game is an concept or story conceit is what you're looking for. Of course, not may people are at the far poles of the axis, so people generally like a bit of both, but they usually have a preference.
GNS is EXTREMELY conceptual. It tries to take all of the nitty gritty details of system design and player experience and abstract them out into these sweeping generalizations in an attempt to explore the idea of "what IS this gaming thing we're doing?". Conceptual people say "Gosh, look at those neat ideas!". Concrete people say "This claims to be about how system affects gameplay, but there's nothing in here about how to make a better system. All it does is try to stereotype me!".
So there's a correlation there. If you are a game designer who thinks conceptually, you will probably make conceptual games, and GNS will probably intrigue you. If you are a game designer who thinks very concretely, you will probably make mechanical games, and GNS will infuriate you.