The kernel did find a way to balance these things. Nothing is being rewritten in rust (nothing core, some modest drivers have been). Hellwig didn't have to worry about Rust at all, could have kept doing his thing.
If we accept this as the core concern:
> Having worked on codebase like that they are my worst nightmare, because there is a constant churn of rewriting parts from language A to language B
Then he has no need to fear, nothing in the foreseeable would have affected him in any way.
He didn't like that he didn't have control over what other people elsewhere were doing. But there was an extremely generous balance offered him, to be utterly unaffected in any way. And that wasn't good enough for him.
You're not wrong, but if one of the main Rust proponents and one of the main anti-Rust proponents both quit, that doesn't strike me as them finding balance.
If we accept this as the core concern:
> Having worked on codebase like that they are my worst nightmare, because there is a constant churn of rewriting parts from language A to language B
Then he has no need to fear, nothing in the foreseeable would have affected him in any way.
He didn't like that he didn't have control over what other people elsewhere were doing. But there was an extremely generous balance offered him, to be utterly unaffected in any way. And that wasn't good enough for him.