> 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].

[0]: https://youtube.com/watch?v=XZ3w_jec1v8

Is the Gnat compiler not sufficiently free and open source? It does not fulfill the comment calling for "toolchain" however.

Edit: Thanks for that video. It is an interesting synthesis ad great context.