gentlefury
iPF Noob
The Windows/Linux PC environment illustrates what happens with an open system. Some good/some bad. Apple has pretty much had a closed system from the beginning. If the device can only run "supplied" software and use certified devices, then the service/repair/upgrade loop becomes much easier to work and the company also makes more money.
The iPad/iPod/iPhone/iTouch environment has reached many more people with the attendant demand for openness. Where that will end up is anyone's guess.
I think the Mac system is brilliant. The system works because the hardware is closed (mostly...you can still put in 3rd party ram and hard drives)....this means they only have a handful of configurations in the wild at any given time....so when there is a software update it positively affects every system. Unlike windows that has to work on any infinite number of setups and is reliant on 3rd party vendors to provide drivers to work.
Also, since they manufacture their systems you can bring it in for repair or replace to any Apple store.
You can still install Windows/Linux on your mac if you choose to....and you can install any number of 3rd party applications....but the closed hardware system provides a MUCH better user experience all around!
This also holds true to iOS....which is an even smaller set of hardware rules.