Lack of internal APIs is not the problem if the putative Rust-based clone doesn't aim to be compatible with Linux drivers written in C, which I think it wouldn'

Lack of internal APIs is not the problem if the putative Rust-based clone doesn't aim to be compatible with Linux drivers written in C, which I think it wouldn't. The real problem is that the Linux kernel ABis to user-land are merely stable, myriad, and poorly documented. Keeping up is not possible. The BSDs, Solaris/Illumos, and Windows all had at least one (sometimes two) attempts at being compatible with Linux kernel user-land ABIs, and all failed due to being woefully incomplete in spite of being huge.