I'm not paid to contribute to the Linux kernel, albeit you may get some reputation benefits out of it. It's mostly a hobby: if it sounds fun, I might do it - otherwise no chance in hell.

Contributing to a C kernel sounds like a thankless job with crappy tooling and high potential for errors - and frankly just brings back horrible memories (ahhh, the segfaults).

Developing in Rust on the contrary is quite enjoyable and I'm definitely more inclined to contribute something.