Designers prune.

Left to its own devices, the mob will augment, accessorize, spam, degrade and noisify whatever they have access to, until it loses beauty and function and becomes something else.

It seems democratic and non-elitist to set it and forget it and let the users take over. But the tools we use (Wikipedia) and the brands we covet (Nike or Ducati) resolutely refuse to become democracies.

-Seth Godin

Note: @brennen takes issue with the Wikipedia example when it comes to feature selection, and convinced me that it's not the best example to make. Although I think maybe the point is that Mediawiki implementation on Wikipedia is controlled, but whether or not the decisions about what is used in Wikipedia is democratic or not, I don't know.