yes, things will naturally stretch to fit if you specify their width as a percentage or don't specify the width. However, this doesn't alway slook good with the graphics. For example, the banner on the forum. the table with all the "heading" information stretches, but it's really ugly with the banner not stretching. Because graphics DON'T stretch, and would generally look bad if they do. So instead of that problem, one solution is just to decide how much of the screen they'll use and stick to that, defining it in terms of pixels. That way it always looks the same. In addition, when the text fills up that much space, you have very long lines. It gets more difficult to move to the correct line after finishing one, and imo, looks tacky
And then some whiney brat who doesn't realize that the whole point of having high resolution display is so you can see multiple windows at the same time comes along and wonders why the display on your website isn't a thousand pixels wide.