This is way too simple to be true. Other sites, like Google, Flickr and the pre-F8 Facebook, made clean design a virtue.

MySpace is about user self-expression, especially for teenagers. Teenage bedrooms don't look like House Beautiful. Also, teenagers have a proven ability to extract signal from greater noise (no really, look it up; they really can read text on wacky complex backgrounds much better than oldsters). So their aesthetics are somewhat different.

Craigslist is not particularly pretty but the usability is very good. Everything is there for an obvious reason. And regarding the rather "default" look -- not only does this save on bandwidth, it actually helps usability. Designers should remember that if they even make non-underlined or non-blue links, they just lost a lot of unsophisticated users.

There's very little the user needs to understand, few barriers to posting or reading, and pages load really quickly. The Craigslist people are the masters of giving you 80% of the value for about 10% coding effort and 1% user effort.

It just indicates that our sense of beauty is broken. Or more accurately, hasn't adapted for web pages evaluation yet.

My guess is that we use, to judge web pages, a sense of beauty that we developed for static graphic arts: painting, typography, advertising etc. It fails to take key points into account: a site's dynamic nature, its complex structure, its usability. My usual experience is that many sites which look shiny on screenshots are a PITA to actually use.

survivorship bias strikes again: for every CL or POF there are thousands of ugly sites which are dead; and the vast majority of popular sites have pleasing designs.