Okay.. so I have an idea. I think that the Spiral knights are like... Mecha Knights MkII. In that I think that the mecha knights were the first creations of the Strangers, and are still down in the clockworks, the testing grounds of the Stranger's creations. Its obvious that they dont work as well as Spiral Knights... they definitely seem to be a sort of prototype.
I also believe that the Spiral Knights did NOT crash on the planet. I think they were just programmed by their Stranger Overlords/Creators to think that. The Clockworks are perhaps a testing ground for the Spiral Knights... or are, indeed, an obstacle between the surface and the Core. IF the Clockwork is NOT a testing ground, and it is indeed merely an obstacle between the Strangers and the Core, then the Spiral Knights were created to collect Minerals.

Maybe the Strangers crashed here, on a hostile planet.

SHARE YOUR SPIRAL KNIGHT PLOT IDEAS HERE.