"fields" is a bit too broad. Not all applications in those fields require a standard or certification. That being said, you're absolutely right that in some cases, it is required.
> In C/C++ world there are companies that implement certified compilers.
That is true. In Rust, this is what we're seeing too; the first certification effort is being led by a company, in concert with the language team itself. This is still ongoing.
> I find it's pretty funny that language, which positions itself as safe replacement for C/C++, can't be used in safety critical applications.
This is overloading the word "safe." Rust has been about memory safety. Not about every possible meaning of the word "safe." Yes, Rust is not yet mature enough for industries with those kinds of requirements. Yes, they are not small fields. They are still smaller than the sum of all fields that do not require them. Rust doesn't have to be applicable for every possible use at the earliest stages of its life to matter.
We'll see how it goes.
And I find that highly problematic. If anything, Ada would be a much better choice for these safety-critical applications.
It's not possible for open source project to do such certifications by themselves. In C/C++ world there are companies that implement certified compilers. Usually, these are pretty shitty compilers that implement only previous standards like C++14.
And here is the problem for Rust. If there is no standard for the language and library, how such companies could implement an alternative compiler? Current Rust editions is not an option because they feel like a bottom line and don't answer the question to what extent the compiler has to be implemented to be called "compliant with Rust 2015".
And those fields aren't small. Usually hundreds of million lines of C/C++ power modern vehicle.
I find it's pretty funny that language, which positions itself as safe replacement for C/C++, can't be used in safety critical applications.