How can a rewrite in a completely different language violate this license? There should also be a clause "Once you looked at the source code you must not write anything with similar functionality .... in any programming language"
Leaked Windows code made Wine and ReactOS devs anxious, since MS could sue over it. On the other hand, I've looked up the keycodes from the Linux kernel for X11 (it's literally just PS/2 with the unused codes being used in place of the E0 keys), and they haven't yet came after us.
It made them nervous because someone might put parts of the original source into Wine. You can't do that in a rewrite in a different language, it doesn't even make sense. The thing the people in this screenshot are gloating about isn't even relevant to this license.
It made them nervous for the same reason emulator devs don't touch leaks with a ten foot pole, giving the megacorp any reason to argue your clean house reimplantation is anything but clean is just asking for trouble.