Like it or not, social media is - in part - a competition. It's a game. Services like Foursquare have caught on to this idea, giving little rewards, such as badges and mayorships, to its top users. The only way to get recognized in the social cloud is to have more friends, more influence, more followers, more badges, more everything.
Digg's active campaign against being elite - a top digger - actually made it less interesting to participate. And while you can still see stats for each Digg users, and even create a top list out of that data (such as this one), trying to achieve greatness on Digg and being shunned for it left a sour taste for many prominent users. The very phrase "top digger" has become almost extinct.
What Digg Should Have Done
Instead of ignoring top users, Digg should have cultivated those power users and put emphasis on other metrics besides the number of promoted stories; number of friends, for example. The list could have been expanded according to Digg's content categories, and power users could have been promoted to others Digg users - something Twitter does. In short, Digg's social graph should have been groomed and nurtured, instead of killed.
Although Digg is still doing well traffic-wise - even better than Twitter, by some metrics - it's in trouble. Recent changes at the helm of the company have indicated that even the leaders of Digg may not be sure in which direction they should be heading. Even more importantly for users, the feeling of camaraderie and unity amongst Digg users is not as strong as it once was. And while Digg's traffic is still formidable, one cannot help but wonder what it could have been had Digg chosen to go in a different direction.
The lesson to be learned for all social media services and networks: measuring influence of individual users, as well as creating and maintaining tools to showcase this influence, are crucial features. It gives users a reason to participate; it gives them satisfaction for a "job" well done; it gives them a way to know they're more successful than others. Just like in real life, taking these away from people will merely make them numb.