Sure, but (1) that ship has sailed for now, there are already Rust bits in the kernel; and (2) a patch email thread is not the best place to start discussing whether Rust has a place in the kernel.

There are no Rust bits anywhere outside drivers, and hopefully that will continue to be the case. This means that mainline Linux kernel has no hard dependency on Rust whatsoever, which also means that Rust can be excised at any point with a minimum of effort.

I'm 100% behind Christoph, the last thing Linux needs is the extra complexity that Rust brings. I'm fairly optimistic that Rust will never be a hard dependency for the foreseeable future.

Is it impossible to just delete the rust parts and go back to pure C?

That ship could come back to port anytime.

That's not a decision that can or should come out of a patch review. I agree it's a possible decision, not something unthinkable. But if it were, it should be taken at a completely different level.

Basically, it's an obstructionist, uncivilized thing to hold up every discussion about a topic that you get to participate in by insisting the topic shouldn't be discussed in this forum. It's perfectly OK to advocate for the removal of Rust from the kernel, it's not ok to bring this up in every random Rust patch while the consensus is that Rust has a place in the kernel.

The kernel doesn't really have a better system mechanism for having these sorts of decisions made unfortunately.

I would quite like my laptop to keep working, and half its drivers are rust…

The Linux drivers can be maintained in a downstream fork. Ultimately that seems to be what upstream wants, unfortunate as that may be.

Then you (and others interested in running Linux on fruit company hardware) can sponsor someone to rewrite those drivers in a way that fits the Linux project.