Well no, actually they explain their reasons for doing it in the article others linked here (https://asahilinux.org/2022/11/tales-of-the-m1-gpu/ https://asahili

Well no, actually they explain their reasons for doing it in the article others linked here (https://asahilinux.org/2022/11/tales-of-the-m1-gpu/ https://asahilinux.org/2022/11/tales-of-the-m1-gpu/, section "A new language for the Linux kernel"), and it sounds pretty convincing - if you start a basically new and very complex driver project, and if there is a language more modern than C that might help you and is officially supported by the kernel, then why not use it?