John Gruber on design:

If people are confused with a design, the problem is with the design, not with the users…. [Smart designers] come up with a design that [isn’t] confusing by encapsulating rather than merely hiding complexity. It’s the difference between actually cleaning up a mess versus just sweeping the mess under a rug.

A good “simple” design will help users to understand what is actually going on, how a thing actually works. A bad “simple” design will leave users just as confused as ever with even less chance of figuring it out, because what they need to see to understand it is hidden.

The full title of the Daring Fireball post was “On Hiding vs. Encapsulating Complexity, in the Context of Twitter’s Experimental Reply Interface,” but Gruber’s insight seems worth holding up on it’s own without the somewhat distracting example provided by Twitter.