I think fundamentally it's because it's a better language than C and more pleasant to write. Sure there will be a lot of old codgers who don't want to learn ne

I think fundamentally it's because it's a better language than C and more pleasant to write. Sure there will be a lot of old codgers who don't want to learn new things (surprisingly common in the tech industry), but eventually they'll retire or die, and new kernel devs will be very unlikely to pick C over Rust. The security thing is definitely a driving force but I think probably not that much just compared to how much easier and more pleasant it is to write correct Rust than correct C (in most cases).