Facebook Applications Look Ugly

I just want to say am not an expert by any means in web development or programming . I barely know any html tags. So I don't know much about facebooks API. Though I really like facebook's user interface, but I hate most of the facebook applications out there, because they don't look as clean. Which too me it seems that they might not be motivating their developers to go for that clean look. Bu I really don't know. I do know that a well though out API always helps. For example all the applications I have seen for the itouch/iphone look really pretty. Also most applications(that have seen) written in cocoa for mac os never really look to bad. I hope they do something to get developer to write some awesome stuff!