In Usability in One Easy Step Joel writes:
All those flame wars you read on the OS bigot websites about user interface issues focus on the wrong thing. Windows is better because it gives you more ways to resize the window. So what? That’s missing the point. The point is, does the UI respond to the user in the way in which the user expected it to respond? If it didn’t, the user is going to feel like they can’t control the interface, and they’re going to be unsuccessful. That’s all there is to it. Something is usable if it behaves exactly as expected. Tattoo this on your forehead. Backwards, so you can read it in the mirror.
Is this guy smart or what? And, I’m getting that tattoo as soon as I can bear the pain.