It's a combination of things. The first is the lack of expertise in existing companies and lack of available hires. Rust is new and has a steep learning curve. I work in a company with 7k+ engineers. Our Rust interest group has less than 20 members and most are beginners. I have never seen Rust mentioned on CVs even once when hiring for Embedded positions.
The second reason is lack of tooling - specifically Functional Safety toolchains that can be used for ISO26262 projects. There are plans by Ferrous to develop one, but it will take years to gain any adoptions [1].
I agree with what you're saying completely and have said so on HN in the past. It's my opinion that Rust won't break through the embedded world until the toolchains are there and I don't see an incentive for the vendors to do that work in the first place.
Tradition and machismo. Also, cost savings if there is a slightest chance that C or assembly produces smaller code. Source: I have worked with embedded software specialists. Including the type who just writes the whole thing in assembly because compiler can't optimize the first C effort.
a thing you’re missing is the cost of code recertification.
tens of thousands of dollars and several months of QA per release means that thanks very much but we’re going to keep using what we have because yours looks nice i’m sure but we don’t care.
The second reason is lack of tooling - specifically Functional Safety toolchains that can be used for ISO26262 projects. There are plans by Ferrous to develop one, but it will take years to gain any adoptions [1].
[1] https://ferrous-systems.com/ferrocene/