Apple does not hate GPL... Apple hates freedom...

Apple does not hate GPL... Apple hates freedom...

If you think about it then you'll understand principal difference between kernel and userspace tools. GCC, CUPS, even WebKit are not really vital for the lock-down schemes. They all can be limited by kernel. Kernel, on the other hand, controls everythig in the computer: without support from the kernel side you can not really limit freedom of user. All such tries can be effectively bypassed by appropriate kernel module. Because kernel controls any access to hardware it can emulate said hardware. As long as kernel is free the whole system is effectively free, if kernel is non-free the whole system is effectively closed! Creator of kernel (even free kernel) can cripple said kernel (like Apple does), but it's not very convenient to do with GPL kernel.

Of course choice of kernel was not really up to Apple: they bought Mac OS X kernel and when the said kernel was in design stage linux was not an option: that's was done in 1985! Linus was a teenager back then and still had few years to learn before he'll try to create it's own "clone" of minix...

But today this problem is acute (linux usage is widespread) - and companies invented few "creative" ways to solve it:
1. TiVoization - freeze the free software and make it non-free this way.
2. Phone industry way - separate "don't tamper with" parts and put them in separate hardware box.
3a. Microsoft way and
3b. IBM's way - put freedom-restricting libraries in a box and connect this box directly to the user program.

So far only Phone industry way and IBM's approach work (first one - in huge number of smartphones around the world, the second one - in PS3). Tivoization (implemented by iPhone and/or PSP) and Microsoft's way of control do not work very well: if you put big and complex system in the "forezen state" sooner or later some bugs in it can be used to unfreeze the system, but as iPhone shows that the approach Apple favors is still classic "freeze everything" one...