I've been increasingly feeling the same way, especially about OS X, but what's the alternative for a developer-friendly desktop operating system that looks and works beautifully (almost) out of the box?
Before everyone here laughs at me, let's start with some disclaimers:
* While not as involved as with some other distros (like Arch or Gentoo), Slackware's install process is still a bit involved; namely, you have to manually setup partitions before starting the install program (the Slackware install environment provides `fdisk` and `parted` for this, and details are well-documented).
* You have to make a single edit in `/etc/inittab` in order to get Slackware to boot into a graphical environment by default.
Once you get past those hurdles, Slackware is pretty much what you're asking for:
* Ships with multiple desktop environments / window managers, including KDE, Xfce, Window Maker, and Openbox (in order from most to least pretty/easy-to-use by default), among others. Even more are available on Slackbuilds.org (see below).
* Most (if not all) Slackware software packages include development headers (unlike most GNU/Linux distributions which have separate `-dev` packages for development headers), making it very convenient if you need to develop against some library.
* The underlying system is simple and easy to troubleshoot; no plethora of fragile moving parts like you see in OS X or Ubuntu.
* Ships with the full GCC suite.
* Fast.
* Things "just work".
* Compatible with a lot of different language runtimes/compilers/etc. (for me, I've seen Erlang/Elixir, Ruby (w/ RVM), Perl, Rust, Julia, and assorted other LLVM-oriented languages work out-of-the-box without needing to deviate from `./configure && make && sudo make install`; not that you have to even `./configure && make && sudo make install`, though (see below)).
* Plethora of third-party software packages available on Slackbuilds.org (installation of which is automatable if you download/install `sbopkg`).
It's not for everyone, of course, but it's worked well for me over the last several years.