The problem with Ada, was the price of the compilers, and that the few UNIX vendors that bothered with Ada, like Sun, it was an additional license on top of the already expensive SunOS/Solaris Developer SDK.
Thus the push for C and C++, alongside security certifications, where those languages feel like using Ada with a C like syntax.
Nowadays we live in a world where developers refuse to pay for their tools like other professionals, but hey, Rust is free beer, not like the several millions per seat licenses used by Ada vendors, of whom there are still 7 vendors in business.
