The author describes how OSX is more open-source friendly, describing also how it comes bundled with developer tools, but I find it incredibly hard to believe that an actual developer will have a hard time finding a better tool online. The apps that come with the OS aren't exactly the best, and just about everyone who's planning to get some work done will find other tools wherever with better libraries and more support.
The author also goes on and on about the UI. The simple taskbar in Windows and Linux is enough for me. Is it really necessary to have to view a thumbnail-esque to change to the window? Alt-Tab is enough.
Security? Please! I'll say again: the developers I know are not stupid. Anyone in their right mind and with some knowledge of computers should know that clicking on an odd-looking ad, or downloading a strange attachment, or accessing a crazy porn site aren't sane things. A combination of Firefox and AdBlock/NoScript can make any OS safe for most people. Unless you have kids who have thumb drives and like to use your computer, contracting a virus that way shouldn't be a concern, either.
The hardware-specific optimization is another problem. iPhone development is booming right now, but what about the rest?
I'm willing to accept "the apple", but presenting bogus arguments isn't convincing.