Based on what i've seen in the clockworks, and what story information i've been able to gather (which is far from everything). A project on the scale of the clockworks would need to have a cause large enough to motivate an entire civilization in to working on it. The most obvious reason I can think of for developing a complex and ever changing maze would be because of something that is a threat to the entire civilization lurking about on the surface of the planet. This could either be some pollutant in the air, something to do with the strangers, rival civilizations, or creatures far more terrifying than anything the clockworks has to offer.
As the story expands and grows, I would like to see the spiral order start coming in to face with the problems of the surface that drove the gremlins and the beasts down, and perhaps force spiral HQ lower and lower in to the planet, and also start forcing the spiral order to not just dive for the core but begin exploring the clockworks laterally. Try to reach gremlin cities or other segmented parts of the surface buy traveling through the clockworks. (I'd like to see that regardless of my hopes of a nightmarish surface. Gathering pieces of the skylark would be a sufficient excuse).
At any rate, the why behind the clockworks is as interesting to me as mystery surrounding King Tinkinzar. Like everything else so far, I don't want the answers all at once, but i would like to start getting clues about the reason behind the clockworks and ideally have these reasons slowly bleed in to the player's experience in game.