Why would you craft all that in CSS, and then use an image to do a simple gradient? Not that I'm claiming there aren't reasons (AFAIK you can't add random dith

Why would you craft all that in CSS, and then use an image to do a simple gradient? Not that I'm claiming there aren't reasons (AFAIK you can't add random dithering to the gradients to make the transition between shades less noticeable) but still - why?