They don't get enterprise, A/UX, mkLinux, OS X Server, Mac Pro tower, all gone now.

Swift's main reason to go open source and have good Linux support was naturally for app developers to be able to use it on server side, which naturally wasn't going to be macOS.

I macOS wasn't required for developing iDevices apps, they would surely sell even less desktops.

If anything, Apple has every incentive to hop on the Linux Foundation train like MS. Just for containers, of course ;)