Interfaces
Sean Timarco Baggaley, you are so fulla shite that you must be an olfactory assault on those near you.
Computers are worth a great deal without the OS that runs them. The biggest value being your ability to hunt down an OS, and put it on there. In a world where the OS isn’t tied to the hardware, they would be completely separate items. The hardware being purchased based on performance, reliability and power consumption; the software based on what you could get it to do, or what additional devices you could convince it to talk to.
A great example is the DD-WRT OS for my router. The native OS that came with this thing was pretty limited, so I upgraded to DD-WRT. DD-WRT itself wasn’t doing all I needed it to do, so I got SSH working on it, and started installing packages. Now I have one that runs a cheap robotic arm; it air gaps itself when it detects certain signatures consistent with some viruses I hate. (It should be noted that particular device is hooked up to my honeypot box, and thus airgapping is a grand thing.)
*Interfaces* only matter to *consumers,* and not even all of them care. (How many people still use [insert OS or GUI you wish to insult here.]) What matters, (the only thing that matters), is what a computer system can actually accomplish, and how much it costs you to get it to do so.
This has nothing to do with interfaces. Businesses are where the real money in computers is, and many of the systems they use are embedded. While some embedded systems run GUIs, many run only command lines. If you think interfaces are so important then go tell a robotics programmer that he needs Mac OS ten-point-ocular-bleeding in order to program his ICs. Or go hunt down programmers for just about any software package that lets businesses actually accomplish things and tell them that the critical component of Windows is Aero.
Computers are there to increase the efficiency of our daily lives; they aren't there to blink and glow and look pretty. Interfaces matter only to the bored and the stupid; what matters is how much time and/or money you must put into a system versus the benefits of efficiency that you receive.