They had some nifty ideas (like Twitter-style following of a user's submitted links), which they probably could've implemented gradually and unobtrusively, taking the time to gather feedback and perfect each one. Instead, it seemed like they had a very brief beta, then parachuted in the entire broken, incomplete thing as a wholesale replacement.
It's still plainly broken. The front page is absurd: 4000+ "votes" on the sponsored link, less than 100 on the real links. Fewer than 10 comments on most of them indicates a community that hasn't just declined, it's died out entirely.
I always thought Superman was flying faster than the speed of light to go back in time and save Lois. Turns out he really was reversing the rotation of the Earth to rewind events. I like my version of the movie better.
It's like a Choose Your Own Adventure for movies. :)
Edit: In the video he orbits the earth faster than light could make the trip. Then again his blur trail is way to big etc so IMO just take it as artistic license / bad science fiction.
A lot of a social media site's success is doing the right thing at the right time.
They did the wrong thing at the wrong time, and it might not be possible for them to find a new right thing or time.