They could only shine in a niche market, like SIGMA is trying with their fp and sd camera (Foveon triple layer sensor)... and DSLR seems to be a safer market for Pentax with huge heritage and strong fan base. The demand for Optical viewfinder in EVF times is there, and will still probably be way higher in the next years when they'll be the only one to care as Nikon and Canon already told they won't release any lens or body anymore with the DSLR technology.