"Dear Reddit, have you forgotten that I switched to you from Digg when they pulled this kind of bullshit?"
They just have a lot more investor money they need to show returns on this time.
Further, I don't know how big the original team was, but I doubt the majority of the founders are still there. It is, largely, approximately, under different management.
The oldest and most stable online communities seem to have the slowest-changing interfaces.