I agree, I know a lot of people aren't huge fans of it but in the long run Linux being GPL2 was a huge factor in its success.

Too late? https://docs.freebsd.org/en/books/handbook/linuxemu/

> I am a bit scared of a Linux ABI-compatible kernel with an MIT license.

What's the threat? Solaris/Illumos, the BSDs, even Windows, have all tried -sometimes more than once- to be compatible with the Linux ABI, and in the end they've all given up because the Linux ABI evolves way too fast to keep up and is underdocumented. Someday someone -perhaps TFA- will succeed in building momentum for a well-defined and highly functional least common denominator subset of the Linux ABI, and that will be a very good thing (IMO) regardless of their choice of license.

I guess you imagine that everyone will switch to Moss and oh-noes!-everyone-will-be-free-to-not-contribute-back!! So what?

Why?

It will be compatible for ~5 minutes:

https://www.kernel.org/doc/html/v4.10/process/stable-api-non...