Good luck finding any software engineers who are proficient in Ada, much less a variant of it. I mean, they're out there: according to the SPARK Wikipedia page

Good luck finding any software engineers who are proficient in Ada, much less a variant of it. I mean, they're out there: according to the SPARK Wikipedia page, it's been used in things like some Rolls-Royce jet engines, some military planes, some air traffic control applications, a cubesat project, etc. But there's orders of magnitude more engineers out there proficient in C and/or C++, plus even if you're willing to train, it's not that easy to find engineers willing to move into something that doesn't have broad industry support and might therefore limit their future career moves. C and C++ are already both used for safety-critical systems. MISRA C is the standard in automotive, and there's civilian (DO-178C) and military standards for C++.