I'm a designer and I hate the look the Reddit -- but frankly I think that's the point of the design! By looking ugly the site communicates "this is a geek zone, and some of us don't wear deodorant!" That branding really appeals to the audience they have captured from slick looking sites like Digg. Keep in mind Reddit is owned by Conde Nast and they have great taste and tons of talent to match -- so if the site is ugly there's a reason for it.
It was about the amount of imgur links and lolcats that get pushed to the front page and which subreddits to subscribe to to have a different reddit experience.