Why some professional web designers use absolute paths instead of relative paths (e.g for CSS, Javascript, images, etc.)?

I used to think that everyone used relative paths (e.g. /styles/style.css). But I wonder why some popuar web designers (e.g. http://www.getfinch.com and http://31three.com/) use absolute paths (http://example.com/styles/style.css).

So basically I'm asking why some professional designers are using absolute paths instead of relative paths?