I'm not against richness, complexity or beauty in web design

Simplicity means:

Use as many pixels as you need, in whatever way you need, to facilitate the communication that needs to happen.

 

Of course, often what you're communicating isn't hard data, but soft information.

Hard data

means facts, like news, stock prices, train times, or how much money is in your bank account...

Soft information

covers the qualitative aspects of communication, like the first impression about the quality of a company, the sense of how approachable a service provider is, and whether you feel a product will be right for you. It can be just as important!

Whether what you're communicating is hard or soft, your pixels count, so use them consciously and with care.

(More about this on the Current Style page). Basically, the vast majority of sites these days are positioned centrally within the browser window. Relatively few are full-screen (liquid) or left-aligned / fixed-size, compared to a few years ago.