Because the old religion is dying.
For most of the IT industry's relatively short life, programmers and nerds have been its High Priests, acting as gatekeepers and controlling every aspect of your access to their religion.
The most blatant exponent of this religion is the Free Software Foundation, which was founded towards the end of the earliest phase of personal computing. This foundation worships the god known as "Open Source"—a god they didn't even invent.
"Open Source" is a programmer-centric concept which is only of direct relevance to other programmers. In the early '80s, when the FSF began, most computer users could be assumed to be either programmers, or at least IT-literate.
Today, 99% of computer users today *don't* know how to program, and a substantial majority would have trouble recognising the power switch, so a programmer-centric approach to IT is a lot less useful. The FSF has become the closest thing the programming community has to a union, including a strong protectionist stance against anything they see as a threat to the status of programmers within the IT industry.
The FSF cannot survive in the world as seen by Apple. Apple's corporate philosophy doesn't see computers as a god-like gift to humanity which must be protected from the unclean masses. Instead, the *user* is placed on the pedestal. His needs *always* come first—even if it means writing applications for Apple's computers is made harder as a result. (For example, it's not uncommon for a major OS X release to break some old APIs to encourage the use of newer, more powerful APIs which offer a richer user experience. Microsoft would be lynched if they tried that.)
Programming, as far as Apple are concerned, is just a job like any other. It's not special. It's not the alpha and the omega of IT any more.
Hence all the fanaticism. It really *is* a religious thing, with programmers and fellow IT-literate nerds on the one side, and consumers on the other. (In the middle is Microsoft, who try hard to please both camps, but with mixed success.)
I used to program computers for a living, but quit many years ago when I realised programming in English was far more fun than programming in C++. (I still program, but only as a hobby.) So I've seen the industry from both sides of the fence.
I think Apple generally get it more right than wrong at the moment. (They're certainly not perfect, but they're getting more hits than misses. I do wish the media would give Ive and his team a bit more credit though.)
However, I feel the FSF is a dinosaur and needs some serious reform to make it more relevant. For example, there's no point in pushing for "GNU / Linux" as the ultimate solution to every single IT problem under the sun.
Linux is a set of tools and APIs, but its future is as a *platform* on which others can build, not as an end in itself. Android is the most obvious illustration of this.
In a similar vein, Ubuntu has achieved about 10 million installs, but I suspect many of their users are only peripherally aware that there's something called "Linux" sitting underneath it, and just refer to it as "Ubuntu".
After all, nobody talks about "BSD" running on Apple kit. People know it as "OS X".