An online visitor is most likely to get irritated if design elements like fonts, colors, menus are not used judiciously and are in a state of disorder. Let there be consistency in the design pattern, using white space as a design element brings harmony among the design elements this greatly influences entices the intended audience.
I think your talking about for a link directory. You are right though, but most link directories other then maybe dmoz ect. They don't actually get much visitors, they get more bots. Which are good for indexing ect. At least in my mind thats what I have found the trend is. How many people actually go on directories any more? They styling is important, that way if you do get visitors they want to stay. White Space, I would prefer more colorful. Sorry if that post was dis-jointed. It was just my unique way of saying it - Caleb -