From my experience in the aviation software world, we spend a great deal more on demonstrating reliability than in producing it. This forces a huge amount of overhead on our projects. This isn't a bad thing, mind you, but it is a thing to consider.
It is hard for a couple engineers to start a new company making these sorts of systems. The only practical way is to have a truly good and demonstrably better solution, or be inside a large corporation with already deep pockets.