The DOD could easily have organized Ada hackathons with a lot of prize money to "make Ada cool" if they had chosen to in order to get the language out of the limelight. They could also have funded developing a free, open source toolchain.
Ironically I remember one of the complaints was it took a long time for the compilers to stabilize. They were such complex beasts with a small userbase so you had smallish companies trying to develop a tremendously complex compiler for a small crowd of government contractors, a perfect recipe for expensive software.
I think maybe they were just a little ahead of their time on getting a good open source compiler. The Rust project shows that it is possible now, but back in the 80s and 90s with only the very early forms of the Internet I don't think the world was ready.
Given how much memory and CPU time is burned compiling Rust projects I'm guessing it is pretty complex.
I'm not deep enough into the Rust ecosystem to have solid opinions on the rest of that, but I know from the specification alone that it has a lot of work to do every time you execute rustc. I would hope that the strict implementation would reduce the number of edge cases the compiler has to deal with, but the sheer volume of the specification works against efforts to simplify.
> They could also have funded developing a free, open source toolchain.
If the actual purpose of the Ada mandate was cartel-making for companies selling Ada products, that would have been counter-productive to their goals.
Not that compiler vendors making money is a bad thing, compiler development needs to be funded somehow. Funding for language development is also a topic. There was a presentation by the maker of Elm about how programming language development is funded [0].
