My view of their prospects is not that bleak. We have a similar concept or business model that we can observe in the custom chopper / boutique bike market. Many of those specialty manufacturers were able to survive and prosper, while others failed. When the market / economy hit some bumps, many more failed.
I had a co-worker that pulled $35k out of his skyrocketing home equity to buy a custom bike that, to me, looked about the same as a normal HD w/ extra chrome. When the housing market collapsed, those sales dried up, and the used bikes went back on the market at about half price or so, and the manufactures declared bankruptcy.
If Motus can sell 200 units per year, they probably can survive. If they can work sales up to 1000 per year, by product improvement and pricing w/o sacrificing quality, they may well turn into another success story like Triumph or Victory.