Fucking hell you could cut the Reddit-tier snark with a knife.
BSD is more binary compatible than Windows. The fact there's less MacOS ports on Linux seems to me like a lack of resources, but if you have a reason beyond 🤓☝️ then I'm genuinely interested.
The binary formats are not compatible, not even the format of the files themselves. Linux uses ELF. MacOS uses MachO.
True, macOS is more or less POSIX at the base but the API Mac applications are written to is not that at all ( Cocoa ). GNUstep exists for a reason. Sadly, it is not very mature. It is certainly not a trivial undertaking though as there have been a number of attempts over decades and nobody has really pulled it off.
The Win32 API on the other hand has largely been implanted on Linux. A few Win32 APIs are even being added to the kernel.
Going the other way is easier. You can port POSIX stuff to macOS fairly easily.
Do you have any posts/reading on the win32 additions to the kernel? I vaguely remember something similar being talked about some time ago, but I can't find anything right now.