the reason for it is, people suck at designing websites. if you look at code for a lot of ebsites, it's filled with tag upon tag of useless useless cells. i blame the people who are too lazy to learn a simple mark up language and rely on image ready and the sliceing tool to do everything for them -- it's like getting a blind man to do it: cells and images are made where they don't need to be. optimization is terrible. plus, you wouldn't use tables to design a business report, so why do it here?

the benefit is, it only loads what it has to load. you can make a fairly complex design with only a couple divs if you know what you're doing.