Apple are never going to provide Linux-style package management tools because the market for them is minuscule compared to Apple's real market: normal people. For normal people, there's the App Store.
It seems like the OP's point is pretty valid to me. I use an OS that gives me what I need to do my job.
No. They aren't. Developers have needs far greater than that of your average everyday user. Apple sells a machine that is the best possible for the greatest number of users, and doesn't really cater to niche markets. I don't get what's surprising about this.
Linux and Windows feel like they exist on opposite ends of the spectrum.
What they don't host is the source or compiled versions of any of the packages in the MacPorts repository - potentially for the same reason they include no GPLv3 software in their OS.
Its kind of like developing on windows, for windows, gota do what u gotta do.
Unfortunately, building the packages and then keeping them current takes quite a bit of infrastructure which is why fink's binary packages are really outdated at times.
The other issue is with runtime-dependencies: Self-compiling packages gives you the freedom to, say, build vim without X11 support. With binary packages, the maintainer (or the packaging system) must create n packages for n possible combinations (if the project doesn't have some dynamic-library based plugin system) which is, again problematic from a resource-requirement perspective.