Diablo 3 was pretty horrible at first too for the same reason. I don't know if you will call that a success or failure though.
Give EA time and Sim City will stabilize as well as D3 has, either because they've expanded hardware, or shrunk their user base.
Success or failure depends on your definition of success here. Successful game, sure. Successful sequel to Diablo 2, it doesn't seem to have the same popularity, and I think the connection issues at launch framed a lot of people's opinions about the game.