After looking at multiple templates in Sitebuilder, it is starting to appear that they were constructed more as visual canvases, not html pages. The html mechanism is there, but the way backgrounds, text boxes, images and navigation are constructed is reminiscent of the layer composition found in a word processor document.

This would go a long way to explain the lack of separation between body elements and page content, and the lack of controls to standardize position and width. Almost everything is drag and drop, and the basic underlying page elements can change from page to page.

In a word processor, that isn't much of an issue. The pages are connected end on end, and the page position of page elements isn't directly comparable. You won't notice a title that shifts 1 pixel shift up or down, right or left. On the other hand, a web pages render one after another, in the same visual space as its predecessor. You do notice position shift in logo, page position, margins and page titles.

A few more tools to control site wide components would make it easier for novices to make their pages more visually coherent.