OS X is not the worst UNIX. Darwin is kind of a shit kernel, but the user land is way more sensibly designed than your typical Linux distro (which is, as OP said, a random collection of junk).
That's because OS X's user land is based on BSD. BSD in general is a much more well thought out UNIX-like OS than Linux. When I made the switch a couple of years back, I was surprised at how simply everything fit together compared to my experiences in the Linux space.
For desktops systems, maybe, but there's a reason almost nobody delivers SAAS stuff on Darwin, even as some do deliver on Windows.
Except for package management.
Don't agree. Self contained app bundles are great. I use homebrew for some stuff and dependencies are a PITA. E.g. multiple incompatible Python versions.