Also it uses the best part of a lens through a vertical slit, not the edges, so it doesn't need a quality optic as much to get good sharp pics. I did a diagram of this relating to a rotating pan camera, but it would still be the same for a swing lens camera.
This would be true if such camera would use a standard lens intended for 24x36mm. But the Horizon uses that standard lens in shorter focal length as it only has to cover 24mm instead of 44mm.
So still the lens must be of high quality over the full angle of coverage