I don't see the difficulty with compiling. Just get out your install disk, open up the optional installs, install XCode. You now have all the standard Unix developer tools (in addition to the XCode app, which you don't have to use).
I agree, I don't see it either. The whole point of my previous comment was to show that OS X ships with so many things that you don't have to install anything to start programming in PHP, Python or Ruby. "Until you have to compile something" refers to the fact that this claim doesn't hold anymore when you have to compile, for example, a native extension to those languages.
