"why did DMR drop it"
They made the trailstar LT in a 18" version (which is pretty much a switchback, only slightly heavier)
And the kinesis decade thingy looks awfully familiar doesn't it, you might even think they could be made by the same company………….
You could argue that the switchback came from the trailstar LT, which came from the trailstar, which realy does make it old (were back in the late 90's now!).
My oppinion on the snapping, they were bought by people looking for lightweight jump bikes (maybe they should have sold it as kinesis rather than DMR?), also the later versions without the ISCG mounts were subtly different to strengthen the headtube welds.
I'm not knocking the morning glory or prince albert, but I think the trailstar came first, and the switchback was an evolution of that
(like the MG and PA, sub5 and 5).