The simple fact that you need Xcode's SDK and homebrew/macports on a machine to get anything done outside of Xcode speaks volumes for using Mac's as development workstations (or, specifically, MacOS).
What does that even mean (besides being incorrect)?
How is the situation different in, say, Windows? Can you compile C/C++ stuff out of the box?
Or Linux, for that matter. In a lot of distros, gcc, make and co have to be installed -- they are not part of the default install.
As for the incorrect part: you don't need XCode. You can just install the "command line tools" package from Apple, that contains compilers, headers etc.
Later, I was surprised to find the Ruby Gems use gxx, make, and autoconf. I thought it was a pure Ruby code package manager, that would just tell me to install some native library if it wasn't there, but no, it wants to download and build for itself using gxx.
"You would have similar issues with almost any other language and environment."
This includes Linux, Windows etc. I singled out MacOS as it was relevant to the parent comment. And, as for "incorrect", I think "command-line tools" and SDK could likely be used interchangeably in this context and saying otherwise is splitting hairs.