At one point in the video he says he's proud that Linux is the only OS (I'm presuming he meant kernel) that is in mobile and desktop/server systems. Correct me

At one point in the video he says he's proud that Linux is the only OS (I'm presuming he meant kernel) that is in mobile and desktop/server systems. Correct me if I'm wrong, but I was under the assumption that OSX and iOS were both based on essentially the same Darwin/XNU kernel?