I think we all “get” simplicity these days, but nevertheless this quote from Paul Graham really sums it up:
It seems strange to have to emphasize simplicity. You’d think simple would be the default. Ornate is more work. But something seems to come over people when they try to be creative. Beginning writers adopt a pompous tone that doesn’t sound anything like the way they speak. Designers trying to be artistic resort to swooshes and curlicues. Painters discover that they’re expressionists. It’s all evasion. Underneath the long words or the “expressive” brush strokes, there is not much going on, and that’s frightening.
When you’re forced to be simple, you’re forced to face the real problem. When you can’t deliver ornament, you have to deliver substance.