Let's see you design an operating system that supports so many devices, components, and applications.

For all this talk about Microsoft's monopoly, they won the war because they allowed anyone to make hardware and software for their operating system.

Apple demanded that you buy EVERYTHING from them.

If your operating system has to support all sorts of software and hardware components that haven't even been designed when you release you OS then of course it's going to be a little less stable then a system in which every component is tested with the OS before they sell it to you.