> to convince Linus and the majority of the core kernel developers
The biggest cost is not them, it's every other C programmer, every other company, the whole industry. It's unrealistic to even think that any significant part of them is going to invest resources into another language just to gain memory safety.
I figure, if you're capable of coming up with an argument which convinces Linus to move away from C, you can use that logic to convince anybody (who is capable of being convinced by logic in the first place).
The biggest cost is not them, it's every other C programmer, every other company, the whole industry. It's unrealistic to even think that any significant part of them is going to invest resources into another language just to gain memory safety.