If the creator of something clearly communicates how to pronounce his creation, that pronunciation becomes the most correct one. Furthermore, if that same creator explicitly states that there is only one way to pronounce it, then it’s even more settled.
And that’s what we have here: Linus says very clearly, in this video, that there’s only one way to pronounce Linux.
…I don’t really care how people pronounce my name, but Linux is always Lih-nix.
End of the debate.