The article only mentions one "guru" - Mark Pilgrim - who is upset that Apple hasn't published the latest source code for the kernel.
If you want to spend time hacking the kernel, Linux is the way to go.
For computer users who aren't interesting in kernel hacking, Get a Mac.
He's more concerned about proprietary data formats, and he has a point. Apple is reasonably good about using open formats, but as the iTunes store shows they will go for lock-in when it suits their purposes.
Get a load of what that guy is switching to: a Chicomm Lenovo special.
http://diveintomark.org/archives/2006/05/30/bye-apple
Thankfully he's taking a beating on his own site.