I tried to install an open source software (kdenlive) on a Mac. For this, I had to install macports. For this, I had to install Xcode. For this, I had to register as a Mac OS developer (no kidding). Then I had to wait about six hours for the ~700MiB to download from Apple's servers. Then I had to figure out which version of Macports would be compatible with Xcode (it happened to be MacPorts-2.0.3-10.6-SnowLeopard.dmg, the Snow Leopard was easy enough to figure out, however the 2.0.3 required trial and error, as most recent version, 2.0.4, is not compatible with Xcode 3.2.2). Then it took close to six more hours to fetch its data (from somewhere http://packages.macports.org).
Same thing on my linux box amounts to:
apt-get install kdenlive
and that's it. Even starting from scratch, installing apt itself, the whole process would take at least one order of magnitude less.
I'm still not decided whether Mac OS is worst or better than Windows, but they are both so bad that they cannot be used except to render a punctual, occasional service at best.